Macro-nutrients
These are needed in large numbers by all types of plants.
This includes: Carbon (C), Hydrogen (H), oxygen (O), Nitrogen (N), Phosphorus (K), Potassium (K), Calcium (CA), Magnesium (MG),

Sulfar (S).
Micro-nutrients: These are needed in small numbers by all plants.
This includes; Boron (B), Copper (CU), Iron (FE), Manganese (MN), Molybdenum (MO).
When lack of Nitrogen is present, plants have stunted growth and leafs turn yellow.
When lack of Phosphorus is present, pour root base, stunted growth and dark green leafs are present.
When lack of potassium is present, end of leafs die and turn yellow on edges. stunted growth and stems weak.



                                FAQs

Q: What is Hydroponic Gardening and what are its advantages?
  A: Simply put, hydroponic gardening is a method of growing plants, without soil, by providing food and water directly to the roots of the plant. By doing so, we eliminate the need for the root system to expand looking for food and water, so the energy normally used by the plant to search for food is used for faster upward growth and fruit production. Since we don't have competing root systems, we can grow significantly more plants using hydroponics in a given area than those grown in soil. In addition, we recirculate the water and nutrients, so hydroponic gardening ends up using a fraction of the water, with no fertilizer run-off. Another primary advantage to hydroponic gardening is control. We can quickly make adjustments as necessary to the strength of the nutrient solution, the pH, temperature, etc. to provide the perfect growing conditions and we eliminate soil as a breeding ground for common garden pests, reducing the need to apply harmful pesticides.

Q: What are the different types of hydroponic systems?
A: There are several types of hydroponic 'systems', but they all accomplish the same thing, bringing the food and water to the roots of the plants. The most popular hobby hydroponic methods are Passive, Ebb and Flow, NFT or Nutrient Film Technique, and Aeroponics. In a passive system, plants sit directly in the nutrient solution and the nutrient solution is oxygenated with an aquarium air bubbler so that the roots don't rot. This is the simplest form of hydroponic gardening. An ebb and flow system has a separate nutrient reservoir with a growing tray directly above. A submersible pump in the reservoir, like the ones used in ponds, is connected to a fill and drain fitting in the growing tray. The pump is plugged into a timer, which automatically waters the plants in the growing tray 3 or 4 times a day for a few minutes each watering. When the watering cycle is finished, the solution drains back into the reservoir, pulling oxygen into the plant root system. Nutrient Film Technique is a system that utilizes sloping gutters or PVC pipe. The plants sit evenly spaced in the gutters and a continuous stream of water and nutrients are pumped into the high side of the gutter. The stream has to be very shallow, no more than 1/8 of an inch deep or so. What happens in NFT is that the roots spread out and intertwine along the bottom of the gutter. The roots in the solution take up the food and water, while those that are growing above the water level take in air and oxygen. Aeroponic systems use a very fine mist or spray directly on the roots of the plants. In other words, the root systems are not submerged with aeroponics, rather the nutrient solution is sprayed directly onto the root system.

Q: What kind of maintenance is required?
A: Maintaining hobby hydroponic systems is really very easy, requiring a minimal amount of time. Daily maintenance should take no more than about 5 minutes, just checking to make sure the nutrient reservoir is topped off and the pH levels are correct. Every couple of weeks, your nutrient solution should be replaced with a fresh batch. The old nutrient can be used to water houseplants or landscape plants around the home.

Q: What is the hardest aspect of hydroponic gardening?
A: Learning to pronounce the word 'hydroponic' correctly! Seriously, while hydroponic gardening may sound like rocket science to many, it is a very easy to master method of gardening.

Q: What is a hydroponic medium?
A: Even though we have eliminated the soil, plants still require a place for their root systems to develop. A hydroponic media is an inert substance that can provide some support for the root system that has no nutrient value. Almost any inert substance can be used. A few examples include sand, gravel, vermiculite, perlite, LECA (lightweight expanded clay aggregate) and rockwool.

Q: What kinds of plants are grown hydroponically?
A: Virtually any kind of plant can be grown with the hydroponic method. The most popular hydroponic crops are lettuce, tomatoes, cucumbers and peppers, which you can now buy in many local supermarkets. Most of the cut flowers delivered in the U.S. are now hydroponic grown as well and home gardeners are discovering the benefits of having a cut flower production system on their balcony or patio.

Q: Are there any drawbacks to hydroponic gardening?
A: Since we don't have a large, supportive root system, heavy fruiting crops like tomatoes and peppers may have to be trellised, depending on the hydroponic system used and variety. Root crops like carrots and potatoes present a special challenge as well, although while a bit more difficult to grow hydroponically, it can be done and with pretty spectacular results as well.

Pinch all lateral shoots to 4 inches. Root shoots if desired, then pot.

Remove flower. Cut stems to 6 inches. Many laterals will start to break.

                       Understanding What PPM Scale To UseCF, EC, PPM 500, PPM 700, TDS...

                                       What's the difference?
          CF and EC are measures of electrically charged nutrient ions in a solution. Pure water will not conduct electricity. Water usually conducts electricity because it is full of impurities, in our case, electrically charged nutrient ions.  The two black dots on the end of Bluelab nutrient probes are called electrodes. When these are placed in a solution, an electrical current passes from one electrode, through the water to the other electrode and counts the number of (EC) electrically charged ions present. This represents the units measured - CF or EC.
           PPM measures parts per million. ppm is known as dimensionless quantities; that is, they are pure numbers with no associated units of measurement. A mass concentration of 2mg/kg - 2 parts per million - 2ppm - 2 x 10-6.
              There are many different scales used for different industries around the world and for many different reasons! Did you even know there are more than two scales? The most widely used scales in Hydroponics are the 500 scale, 650 scale and the 700 scale.
              What's the difference? The ppm 700 scale is based on measuring the KCl or potassium chloride content of a solution. The ppm 500 is based on measuring the NaCl or sodium chloride content of a solution and is also referred to as TDS - total dissolved solids. Individual nutrient ions have different electrical effects! The true ppm of a solution can only be determined by a chemical analysis. ppm cannot be accurately measured by a CF or EC meter. They are present on Bluelab products as a conversion guide only. The conversion is as follows:
                                                   2.4EC x 500 = 1200ppm (500 scale) or 1200ppm / 500 = 2.4EC
                                                   2.4EC x 700 = 1680ppm (700 scale) or 1680ppm / 700 = 2.4EC

If you are reading from a book that says you should grow your crop at 1100ppm - how do you know which scale the writer is referring to? Is the scale on your ppm meter right for the job? If the book was written in the USA, it could be the 650 or 500 scale. If the book is written in the UK, it could be the 700 scale. If it was written in Australia, well it could be any of the three!
                 If you must grow using ppm, you will need to know the following;
What ppm scale is the book referring to? What ppm scale is your meter using? Which standard or calibration solution should you use for your meter? What ppm scale is the nutrient formula referring to?(Courtesy of BlueLab)
-------------------------------------------------------------------------------------

At GYOstuff, we do the research so you don't have to. So let's get to it... What PPM scale is your nutrient formula referring to?
Manufacturer                Scale

Advanced Nutrients            700 scale
Botanicare                    700 scale
CES/Cutting Edge Solutions        500 scale
Dutch Master                500 scale
 Dyna-Gro                    500 scale
FoxFarm                    700 scale using dechlorinated tap water
General Hydroponics             500 scale using reverse osmosis water
General Organics             500 scale using reverse osmosis water
House & Garden                 700 scale
Humboldt Nutrients             500 scale
Hydro Organics/Earth Juice            500 scale
Nectar for the Gods            700 scale
Rock Nutrients                700 scale
Roots Organics                500 scale
Technaflora                 500 scale

Now that you know which scale to use, check out our selection of meters.
           Also handy is this PPM conversion chart:

​​​Mikes Nursery and Hydroponic Growing Supplies
199 East Fairmount Ave. 
Lakewood, NY  14750
716-763-1612

          SEPT. 20 until DEC. 1
Keep in light only from 8 a.m. to 5 p.m. Put in dark place (no lights) 5 p.m. to 8 a.m.

                    Prolific Plant Probiotic


Put P3 ’s good bacteria to work for you... in the garden!

Modern commercial agriculture has for decades utilized a secret tool that is now available to the home gardener. It is a natural solution to improving the soil ecosystem and increasing yields by enhancing the plants’ ability to uptake nutrients and fend off pathogens and fungus: Bacillus microbes.

You likely know the power of “probiotics” to improve your digestive health. Plants, too, can benefit in many of the same ways we do with the introduction of the proper bacteria . That’s what  P3 Prolific Plant ProbioticTM  is all about.Bacillus microbes in P3 are proven to have a positive impact on plant health and yields when farmers inoculate their fields with these friendly bacteria. These Bacillus microbes are on the GRAS (Generally Recognized as Safe) list for animal feed and agriculture. They are safe and easy to use.

Here’s what they do:

Bacillus microbes break down nutrients (nitrogen, potassium, potash, etc...) in the soil, making them easily assimilated by the plant,
Bacillus colonize the roots and rhizomes, assisting and enhancing the assimilation of those nutrients,
Bacillus produce enzymes and other metabolites that ward off pathogens and fungus which attack the plant at the roots. when introduced in abundance, they literally create a ‘zone of inhibition’ around the root ball,
Many Bacillus strains process, or “fix,” atmospheric nitrogen so plants can easily uptake this compound,
Bacillus may also digest oil in the soil which can convert hard to garden clay into loose friendly top soil.

Many farmers from the U.S. to Asia have seen yields go up 30+% and found their use of traditional fertilizers has dropped the same percent or more!

These “plant probiotics” usually come in three forms: liquid, powder and pellets. All three forms may be amended with various nutrient packages and vary on ease of use.

P3 Prolific Plant Probiotic™ -- an easy to use pellet form -- is supercharged with MICRO-nutrients and amino acids.

Here are a few important tips:

P3  can be used anytime in the lifecycle of a plant. It’s never too late to begin using them, Plants will benefit from P3   year ‘round. In fact Autumn is when plants stop producing leaves and blooms and fruit, and focus on root growth. This is an ideal time to provide  P3 to your perennial plants.


It’s best to provide small doses regularly versus a huge one-time dose. This prevents a spike & crash growth curve, instead resulting in steady prolific growth through the plant’s peak fruit or flower producing phase,


Unlike human probiotics, which you can often feel working in days, you need to rely on your eyes for results. Make sure you set aside at least one similar plant that does not get treated with P3 so 2-4 weeks later you can actually see the difference,


Like all probiotics, there are weak products and strong products. The more CFUs (Colony Forming Units) per gram, the better your results will be.  P3 has the strongest dose of any similar product on the retail market. 


These Bacillus spores are very stable; moisture in soil reverts them to their vegetative state; shelf life is infinite if kept dry between 50F & 80F. Unlike liquid products, P3 does not need a stabilizer additive.


Bacillus Subtilis
- Well known cattle feed ingredient
- Spores are viable for decades; common soil inoculant: frees up nutrients from food sources
- Symbiotic with roots as a colonizer; antagonistic to pathogens

Bacillus Licheniformis
- Found in soil and on bird feathers
- Protease producer (especially breaks down feathers)
- Biological “laundry detergent”
- Adapts well to alkaline areas

Bacillus Amyloliquefaciens
- Source of the BamH1 restrictive enzyme (stifles virus and pathogens)
- Source of Subtilisin, an organic “laundry detergent”
- Causes starch hydrolysis of green plants
- Produces Barnase, an antibiotic protein

Bacillus Pumilis
- Anti-fungal
- Colonizes roots to prevent fungus formation
- Highly stress resistant

All are considered “rhizobacteria” for they breakdown atmospheric nitrogen into a compound easy to uptake by plants.

                                                              Diagnosing Calcium Deficiencies and Magnesium Deficiencies
      

        Calcium is an immobile element.  In other words, once it is locked up in the plant tissue, it can’t be translocated to other parts of the plant.  So a calcium deficiency normally shows up in the new growth at the growing tips of the plant, causing deformed leaves and reduced root growth.  There may be plenty of calcium in the nutrient formula, but anything that interrupts the flow of water in the plant could cause a calcium deficiency.  For example, if relative humidity is too high, the plant may not transpire enough water to transport calcium
     to all of the cells of the plant.  As a result, calcium deficiency may show up as tip burn in lettuce or blossom end rot in tomatoes.  High temperatures, stagnant air and over fertilizing can make the calcium deficiency even worse.  So before reaching for a bottle of            calcium/magnesium supplements, make sure that your environment is under control, first.Magnesium, on the other hand, is a mobile element.  In other words, if there is a magnesium deficiency the plants will strip magnesium out of the lower leaves and transport it to the new growth where it is needed the most.  So magnesium deficiency shows up first as interveinal  chlorosis on the older, bottom leaves.  Magnesium is the central element in chlorophyll, the green pigment in plant leaves.  So if there is a magnesium deficiency, the veins of the lower  leaves will stay green, but the tissue between the veins will turn yellow. 

      Magnesium deficiencies are fairly common in indoor gardens.  Indoor gardeners often use powerful HID grow lamps such as metal halide or high pressure sodium.  As the light becomes more intense, the plants need more magnesium to efficiently utilize the light energy. That’s why the symptoms of magnesium deficiency are often more obvious in gardens that have more intense light, and magnesium supplements are sometimes required.
      Cal/mag supplements are commonly prescribed to treat calcium and magnesium deficiencies.  Since magnesium is so biologically active, calcium is often used as a buffer.  The calcium slows  down the uptake of magnesium so that excessive magnesium doesn’t accumulate in the
    leaves and become toxic to the plant.  For best results, most cal/mag formulas will provide      calcium and magnesium in about a 5:1 ratio.  The calcium and magnesium compete with one another for uptake by the plant roots, helping to provide balanced uptake.
        Not all calcium/magnesium supplements are alike!  So make sure you carefully read the labels  to find out what sources the calcium and magnesium are derived from.  Calcium and magnesium supplements may be derived from carbonates, nitrates or sulfates.

                        Magnesium Supplements
         If you want a quick fix for a magnesium deficiency, without any extra nitrates or bicarbonates, the     best solution may be to use a magnesium sulfate supplement without the calcium. 
      Magnesium sulfate is fast acting, highly soluble, and may be used safely at the roots or as a  foliar spray.  Since it contains no nitrates, magnesium sulfate is an excellent choice during  flowering.  In fact, many “sweet” products designed specifically for flowering are loaded with magnesium sulfate.  The magnesium helps keep the sugars flowing all the way to the day of harvest, and the sulfates are an added bonus.  Sulfate compounds actually help turn on flowering genes in the plant, contribute to aromas, and hasten the ripening process.

Copyright © Mike's Nursery. All rights reserved 1999 to 2017, and still going strong. 

Take inside.

Repot in larger pot if necessary. Plant outside in pot.

                                                  General pH Information



                                                                               What is pH?

A pH (potential of Hydrogen) measurement reveals if a solution is acidic (BASE) or alkaline (BASIC). If the solution has an equal amount of acidic and alkaline molecules, the pH is considered neutral. Very soft water is commonly acidic, while very hard water is commonly alkaline, though unusual circumstances can result in exceptions.The pH scale is logarithmic and runs from 0.0 to 14.0 with 7.0 being neutral. Readings less than 7.0 indicate acidic solutions, while higher readings indicate alkaline or
 base solutions. Some extreme substances can score lower than 0 or greater than 14, but most fall within the scale.

                                             What is automatic temperature compensation (ATC)?

When measuring pH using a pH electrode the temperature error from the electrode varies based on the Nernst Equation as 0.03pH/10C/unit of pH away from pH7. The error due to temperature is a function of both temperature and the pH being measured. Temperature compensation can be achieved manually or automatically. Manual temperature compensation is usually achieved by entering the temperature of the fluid being measured into the instruments menu and then the instrument will display a "Temperature Compensated" pH reading. Automatic temperature compensation requires input from a temperature sensor and constantly sends a compensated pH signal to the display. Automatic temperature compensation is useful for measuring pH in systems with wide variations in temperature. 

                                                                                     EC/TDS

                                                                                            What is EC?

      Electrical Conductivity (EC) is defined by the ability of a solution to conduct an
    electrical current.

                                                                                        What is TDS?

     Total Dissolved Solids (TDS) is defined as the amount of solids dissolved in a solution.

                                                                                            What is their relationship?

      The relationship between the amounts of solids such as salts found in fertilizers is directly        proportional to their conductivity, therefore, the higher the amount of solids the greater
the conductivity. This is because when fertilizers are dissolved into water they become "ions", which means that they become positively or negatively charged and can therefore conduct a    current.

                                                                     

                                                                                 How does an EC/TDS meter work? 

             Two electrodes with an applied AC voltage are placed in the solution. This creates a current    dependent upon the conductive nature of the solution. The meter reads this current and displays in either conductivity (EC) or ppm (TDS).

              Conversion Factors

      TDS meters read the conductivity; the meter automatically converts this value to TDS which is typically displayed in ppm.

                                                        Tech. info



   HumboldtNutrients2009ProductGuide_2180.html 

    foxfarm_hydro.html


        gen_hydr_recirc.html


              New_Feed_Chart.html


COSYS & COSYS20 Instructions 2013-2015                               CO2 Flow Rate Calculator
                                                               

Active Aqua Water Pump Instructions                             Active Aqua Pump Flow Rates (GPH)
                


Diagnosing Nutritional Deficiencies

Introduction
The correct diagnosis of nutritional deficiencies is important in maintaining optimum plant growth. The recognition of these symptoms allows growers to "fine tune" their nutritional regime as well as minimize stress conditions. However, the symptoms expressed are often dependent on the species of plant grown, stage of growth or other controlling factors. Therefore, growers should become familiar with nutritional deficiencies on a crop- by-crop basis. 

Record keeping and photographs are excellent tools for assisting in the diagnosis of nutrient deficiencies. Photographs allow growers to compare symptoms to previous situations in a step-by-step approach to problem solving. Accurate records help in establishing trends as well as responses to corrective treatments.

Because plant symptoms can be very subjective it is important to approach diagnosis carefully. The following is a general guideline to follow in recognizing the response to nutrient deficiencies:

Macronutrients:

Nitrogen(N) - Restricted growth of tops and roots and especially lateral shoots. Plants become spindly with gen eral chlorosis of entire plant to a light green and then a yellowing of older leaves which proceeds toward younger leaves. Older leaves defoliate early.

Phosphorus(P) - Restricted and spindly growth similar to that of nitrogen deficiency. Leaf color is usually dull dark green to bluish green with purpling of petioles and the veins on underside of younger leaves. Younger leaves may be yellowish green with purple veins with N deficiency and darker green with P deficiency. Otherwise, N and P deficiencies are very much alike. 

Potassium(K) - Older leaves show interveinal chlorosis and marginal necrotic spots or scorching which progresses inward and also upward toward younger leaves as deficiency becomes more sever.

Secondary Nutrients:
Calcium (Ca) - From slight chlorosis to brown or black scorching of new leaf tips and die-back of growing points. The scorched and die-back portion of tissue is very slow to dry so that it does not crumble easily. Boron deficiency also causes scorching of new leaf tips and die-back of growing points, but calcium deficiency does not promote the growth of lateral shoots and short internodes as does boron deficiency.

Magnesium (Mg) - Interveinal chlorotic mottling or marbling of the older leaves which proceeds toward the younger leaves as the deficiency becomes more severe. The chlorotic interveinal yellow patches usually occur toward the center of the leaf with the margins being the last to turn yellow. In some crops, the interveinal yellow patches are followed by necrotic spots or patches and marginal scorching of the leaves.

Sulfur(S) - Resembles nitrogen deficiency in that older leaves become yellowish green and the stems become thin, hard, and woody. Some plants show colorful orange and red tints rather than yellowing. The stems, although hard and woody, increase in length but not in diameter.

Micronutrients:
Iron (Fe) - Starts with interveinal chlorotic mottling of immature leaves and in severe cases the new leaves become completely lacking in chlorophyll but with little or no necrotic spots. The chlorotic mottling on immature leaves may start first near the bases of the leaflets so that in effect the middle of the leaf appears to have a yellow streak.

Manganese(Mn) - Starts with interveinal chlorotic mottling of immature leaves and, in many plants, it is indistinguishable from that of iron. On fruiting plants, the blossom buds often do not fully develop and turn yellow or abort. As the deficiency becomes more severe, the new growth becomes completely yellow but, in contrast to iron necrotic spots, usually appear in the interveinal tissue.

Zinc (Zn) - In some plants, the interveinal chlorotic mottling first appears on the older leaves and in others, it appears on the immature leaves. It eventually affects the growing points of all plants. The interveinal chlorotic mottling may be the same as that for iron and manganese except for the development of exceptionally small leaves. When zinc deficiency onset is sudden such as the zinc left out of the nutrient solution, the chlorosis can appear identical to that of iron and manganese without the little leaf.

Boron (B) - From slight chlorosis to brown or black scorching of new leaf tips and die-back of the growing points similar to calcium deficiency. Also the brown and black die-back tissue is very slow to dry so that it can not be crumbled easily. Both the pith and epidermis of stems may be affected as exhibited by hollow stems to roughened and cracked stems.

Copper(Cu) - Leaves at top of the plant wilt easily followed by chlorotic and necrotic areas in the leaves. Leaves on top half of plant may show unusual puckering with veinal chlorosis. Absence of a knot on the leaf where the petiole joins the main stem of the plant beginning about 10 or more leaves below the growing point.

Molybdenum(Mo) - Older leaves show interveinal chlorotic blotches, become cupped and thickened. Chlorosis continues upward to younger leaves as deficiency progresses.
Proper nutrition is one of the most critical factors in the production of nursery/floral crops. Generally speaking, most of these plant materials may be classified as "heavy feeders", requiring relatively large quantities of fertilizers. However, the ratio and sources of elements supplied are as important as their amounts.

Research has shown that the balance between nitrate (NO3), nitrogen (N) and ammonium (NH4) can effect plant growth. In Texas it is recommended that no more than 50% of the N supplied should be in the NH4 form. Increased amounts of NH4 in the growing media may result in severe ammonium toxicity of foliage burn.
Most Texas growers currently incorporate superphosphate into their growing media as a source of P. However, because superphosphate is relatively insoluble, the amount of P released during the growing season is often not sufficient.

Some growers also supply phosphorus (P) in the form of phosphoric acid (H3PO4). This is done both to supplement P nutrition as well as to help acidify alkaline irrigation water. .

Potassium (K) is a key element in maintaining poinsettia nutrition. At present most growers supply K in the form of potassium nitrate (KNO3). This material which contains both K and NO3 is an excellent fertilizer for use on potted crops. Research has also shown that a 1:1 balance between N and K2O is optimum.

Another important aspect of nursery/floral crop nutrition involves the secondary elements calcium (Ca) and magnesium (Mg). Due to continuous leaching during irrigation, these nutrients can run in short supply late in the growing season.

Most fertility programs designed for nursery/floral crop production supply Ca in the form of calcium nitrate. However, growers using pre-mixed fertilizers are generally recommended to make some supplemental applications of calcium nitrate near the end of the growing season. 

Unlike Ca, most custom mixed fertilizer solutions do not contain Mg as a principal component. For this reason dolomitic lime is frequently used, not only to adjust pH, but also as a source of Mg. Once again, due to continuous leaching during irrigation, Mg levels in the medium can become low. Under these circumstances supplemental Mg may be applied in the form of magnesium sulfate (epsom salts).

Perhaps the most commonly used method to apply fertilizer is through a nutritional regime referred to as constant fertilization. This system involves the application of soluble fertilizers at very irrigation. The most important factor in this fertilization program is to apply enough water at each irrigation to leach to pots thoroughly. This prevents the accumulation of soluble salts from previous irrigations.

Many growers also use a controlled release fertilizer in combination with a constant fertilization program. Generally speaking 4 - 6 lbs/cu. yd. of growing media (14-14-14) may be used to supplement a nutritional program. However, water quality must also be taken into consideration. Caution should be used in determining if a controlled release fertilizers are appropriate.

    Most fertility programs are designed around the macronutrients (N,P,K). In fact, when we discuss these fertility regimes we usually describe them as 150 parts per million (ppm) or 200 ppm, etc. This, of course, refers to the amount of nitrogen in solution, regardless of the analysis of the material used to make it up (i.e. 20-10-20, 15-16-17, 29-20-20, etc.). I guess phosphorus and potassium nutrition aren't that critical to plant growth or maybe we're just lazy.

The micronutrients are important too and growers frequently use a micronutrient supplement to meet crop needs. These can be pre-incorporated in to the growing media or added as a soluble application/drench. Since most of these micronutrient supplements are a "package" (containing all of the essential micro's) there is always some concern about getting too much of one and not enough of another. 

Frankly, we don't see many problems with N,P,K deficiencies or toxicities. These fertilizer materials are cheap and easy to use and most crops are pretty forgiving as long as you are on the high side of the recommended rate. When it comes to micronutrient nutrition, most of the problems we see are related to pH and alkalinity. These two factors, in media and water, effect availability. When out of range (i.e. pH >7.0, alkalinity>150 ppm) deficiencies can occur regardless of the concentration of micros in the water/media. Most growers find a way to work around this problem by: acid injecting their irrigation water, using acid forming fertilizers, increasing micronutrient levels, using tolerant cultivars, etc.

Where we do see reoccurring nutrient problems is with the "secondary nutrients." This is a term used to describe calcium, sulfur and magnesium. There has been a lot of discussion lately on both calcium and sulfur. These nutrients are often present as a component of complete N,P,K fertilizers but may be required in higher concentrations for optimum plant growth. However, it's magnesium (Mg) that can give Texas growers fits during the spring and summer months.

The primary source of Mg in most fertility programs is from dolomitic lime. This material is incorporated to raise pH and increase buffer capacity. Dolomitic lime is usually used at a rate of approximately 4-6 pounds per cubic yard of mix. In many cases this is the only source of Mg provided for plant growth.

Most greenhouse crops are on the bench for a relatively short period of time (i.e. 6-12 weeks). During this cycle plants may be irrigated once, twice or in some extreme cases even three times per day. As a result, much of the incorporated dolomitic lime (Mg) may be leached from the container. This is even more of a problem on longer term crops (i.e. >20 weeks).

Magnesium deficiencies are pretty easy to spot. Most plants develop a very distinctive, interveinal chlorosis on the middle to upper leaves. However, I've seen these same symptoms from the top of the plant to the bottom. Generally speaking, this condition cannot be corrected once it occurs so be on the lookout early in the crop. In severe situations the entire plant may defoliate. 

This problem is relatively simple to take care of. Supplemental applications of magnesium sulfate (Epsom salts) during the growing season. The only complication is that Epsom salts can't be tank mixed with your regular N,P,K solution. The resulting precipitate will clog up drip emitters and other pieces of irrigation equipment. Therefore, separate drench-type applications are necessary. Generally speaking one application midway through the crop should be sufficient unless excessive leaching is apparent. Some complete fertilizer products have a Mg component which makes it a little easier to use.

Table 1 presents a variety of injection ratios and the amount of magnesium sulfate required to make up a low and high rate of Mg.

Symptoms:
Interveinal chlorosis, stunting and defoliation.


Magnesium deficiencies usually appear as a yellowing between the veins of the leaf. This situation is rarely correctable. entire plant affected.

Crops Affected:
Almost all greenhouse crops can be susceptible to Mg deficiencies.

What to Do:
Use pre-plant dolomitic lime and/or supplemental applications of magnesium sulfate.
Magnesium Nutrition

Most fertility programs are designed around the macronutrients (N,P,K). In fact, when we discuss these fertility regimes we usually describe them as 150 parts per million (ppm) or 200 ppm, etc. This, of course, refers to the amount of nitrogen in solution, regardless of the analysis of the material used to make it up (i.e. 20-10-20, 15-16-17, 29-20-20, etc.). I guess phosphorus and potassium nutrition aren't that critical to plant growth or maybe we're just lazy.

The micronutrients are important too and growers frequently use a micronutrient supplement to meet crop needs. These can be pre-incorporated in to the growing media or added as a soluble application/drench. Since most of these micronutrient supplements are a "package" (containing all of the essential micro's) there is always some concern about getting too much of one and not enough of another. 

Frankly, we don't see many problems with N,P,K deficiencies or toxicities. These fertilizer materials are cheap and easy to use and most crops are pretty forgiving as long as you are on the high side of the recommended rate. When it comes to micronutrient nutrition, most of the problems we see are related to pH and alkalinity. These two factors, in media and water, effect availability. When out of range (i.e. pH >7.0, alkalinity>150 ppm) deficiencies can occur regardless of the concentration of micros in the water/media. Most growers find a way to work around this problem by: acid injecting their irrigation water, using acid forming fertilizers, increasing micronutrient levels, using tolerant cultivars, etc.

Where we do see reoccurring nutrient problems is with the "secondary nutrients." This is a term used to describe calcium, sulfur and magnesium. There has been a lot of discussion lately on both calcium and sulfur. These nutrients are often present as a component of complete N,P,K fertilizers but may be required in higher concentrations for optimum plant growth. However, it's magnesium (Mg) that can give Texas growers fits during the spring and summer months.

The primary source of Mg in most fertility programs is from dolomitic lime. This material is incorporated to raise pH and increase buffer capacity. Dolomitic lime is usually used at a rate of approximately 4-6 pounds per cubic yard of mix. In many cases this is the only source of Mg provided for plant growth.

Most greenhouse crops are on the bench for a relatively short period of time (i.e. 6-12 weeks). During this cycle plants may be irrigated once, twice or in some extreme cases even three times per day. As a result, much of the incorporated dolomitic lime (Mg) may be leached from the container. This is even more of a problem on longer term crops (i.e. >20 weeks).

Magnesium deficiencies are pretty easy to spot. Most plants develop a very distinctive, interveinal chlorosis on the middle to upper leaves. However, I've seen these same symptoms from the top of the plant to the bottom. Generally speaking, this condition cannot be corrected once it occurs so be on the lookout early in the crop. In severe situations the entire plant may defoliate. 

This problem is relatively simple to take care of. Supplemental applications of magnesium sulfate (Epsom salts) during the growing season. The only complication is that Epsom salts can't be tank mixed with your regular N,P,K solution. The resulting precipitate will clog up drip emitters and other pieces of irrigation equipment. Therefore, separate drench-type applications are necessary. Generally speaking one application midway through the crop should be sufficient unless excessive leaching is apparent. Some complete fertilizer products have a Mg component which makes it a little easier to use.

Table 1 presents a variety of injection ratios and the amount of magnesium sulfate required to make up a low and high rate of Mg.

Symptoms:
Interveinal chlorosis, stunting and defoliation.

Magnesium deficiencies usually appear as a yellowing between the veins of the leaf. This situation is rarely correctable. entire plant affected.

Crops Affected:
Almost all greenhouse crops can be susceptible to Mg deficiencies.

What to Do:
Use pre-plant dolomitic lime and/or supplemental applications of magnesium sulfate.

Nitrogen and Nitrogen Fertilizers

Nitrogen (N) is a key nutrient in manipulating plant growth. Most nursery/floral producers use large quantities of N fertilizers in a "blanket" attempt to meet the needs of their crops. However a thorough understanding of N nutrition Can be useful in optimizing both the concentration and form of N best suited for the plant species, stage of growth, time of year and production objectives.

Plants require N in relatively large quantities and in forms that are readily available.

Nitrogen metabolism is a well studied and a vital aspect of plant growth. Nitrogen is one of the important building blocks in amino acids:  H    R C COOH      NH2 
Amino acids are typically made up of an amino group (NH2), carbon (C), a carboxyl group COOH), and a variety of molecular structures (R) which define individual amino acids (glycine, serine, licine, alanine, etc.). When these amino acids link together in long chains they form proteins. Proteins are also vital components in a variety of metabolic pathways and processes. Proteins makeup the molecular structure of DNA, RNA and a host of other critical metabolic processes required for plant growth. 

When N is deficient in plants restricted growth of tops and roots and especially lateral shoots may occur. Plants also become spindly with a general chlorosis of entire plant to a light green and then a yellowing of older leaves. This condition may proceed toward younger leaves. Older leaves defoliate early.Plants can take up N in 4 forms:

NH4 Ammonium  NO3 Nitrate  Organic Nitrogen  Molecular Nitrogen

Regardless of the N source (inorganic fertilizer, organic fertilizer, manure, etc.) plants can only take up N in these 4 forms. That means that some conversions must occur in the growing media/root zone (rhizosphere) before some sources of N can be taken up by the plant. All 4 forms of available N have unique characteristics that influence plant growthin different ways. Understanding these characteristics is very important in matching the best N fertilizer with plant species, stage of growth, time of year and production objectives. The following is a brief description of these 4 N forms and some additional information on the most common fertilizer sources for each.

Nitrate NO3 and Ammonium NH4 Nitrogen: 
The roots of most plants absorb N from the growing medium in the form of NO3. Nitrogen in this form, however, is not directly used by the plant but must be reduced to ammonia (NH3) before it can be assimilated by the plant. The process of nitrate reduction to ammonia is a 3 step process:

NO3 a NO2 a NH3 
Nitrate Nitrite Ammonia

This conversion is dependent of the presence of several enzymes (i.e. nitrate reductase) for the conversion to complete it's cycle. These enzymes, and the microorganisms that indirectly produce them, are effected by several factors including: temperature, moisture, etc. If the conversion process stops at the nitrite stage serious damage may occur. Nitrite is toxic to plants at low to moderate levels and can cause significant reductions in growth at low levels.

Both nitrate and ammonium fertilizers are commonly used to provide supplemental nutrition for nursery/floral crops. Ammonium (NH4) fertilizers must first be converted to nitrate NO3 before it can be used by the plant. This is a 2 step process in which ammonium is first converted to nitrate and then the nitrate is subsequently converted to ammonia. This process, known as nitrification, is dependent on several soil microorganisms (Nitrosomnas, Nitrobacter). These microorganisms are effected by several factors including: temperature, moisture, etc.

2NH4 + 3O2 a 2NO2 + 2H2O + 4H
Ammonium Oxygen Nitrate Water 
and then
NO2 + O2 a 2NO3 
Nitrite Oxygen Nitrate

Ammonium is the most common, and perhaps the lowest cost supplemental source of N for plant growth. Research has shown that the balance between nitrate (NO3), nitrogen (N) and ammonium (NH4) can effect plant growth. In Texas it is recommended that no more than 50% of the N supplied should be in the NH4 form. Increased amounts of NH4 in the growing media may result in severe ammonium toxicity (nitrites??).

Organic Nitrogen:
Many plants are capable of using organic, as well as inorganic N. As they breakdown in the growing medium, many of the amino acids, amides and proteins provide available N for plant growth. However,
urea is perhaps the most commonly used source of organic N for nursery and floral crops. 
O    NH2 C NH2
Urea must first be converted to ammonia before it can be used by the plant. This conversion is dependent on the enzyme urease. Urease is another compound that is effected by factors such as temperature, moisture, etc.
O
NH2 C NH2 a 2NH3 + CO2
Urea Ammonia 
Under cool temperatures urease is often rendered inactive and little, if any, N is available for plant growth.

Molecular Nitrogen:
Many plants are capable of fixing N directly from the atmosphere (legumes). This process usually requires the indirect mediation of soil microorganisms. Perhaps the best example of N fixation is in soy beans. Beans are inoculated with specific N fixing microorganisms prior to planting. Nodules are then formed on the root system which indirectly provide atmosphereic N to the plant.

Although several nursery/floral crops have the capability to fix N from the atmosphere, most growers provide supplemental fertility to compensate for the potential lack of these specific microorganisms in soilless growing substrates.
Micronutrient Management

Plant nutrition is extremely important in the production of foliage, flowering and bedding plants. Generally speaking, most growers use some complete fertilizer to supplynitrogen (N), phosphorus (P), and potassium (K). These elements are referred to as macronutrients because they are required in relatively large quantities for plant growth and development. Boron (B), chlorine (Cl), copper(Cu), iron (Fe), manganese (Mn), molybdenum (Mo) and zinc (Zn) are referred to as the micronutrients because they are needed by the plant in much smaller quantities than the macro's.

Providing optimum micronutrient levels can be challenging. Although many pre-mixed growing medium have a "micronutrient charge", most are only designed to last for 2 - 3 irrigations. This means that some additional micronutrient source must be supplied to meet the nutritional needs of the plant. The primary considerations for micronutrient fertilization include: source used, amount provided, and availability or form.

There are a variety of sources that can be used to supply micronutrients. Several "complete packages" are available that supply all 7 elements. These can either be incorporated in to the growing medium or applied through the irrigation system. However, there is a risk of putting out too much or too little of a specific nutrient using this shotgun approach.

Many soluble N,P,K fertilizers also provide some level of micronutrients. If properly selected this approach is ideal for providing a constant, low-level source of micro's for plant growth. Study the label carefully to determine the amounts supplied and be sure the product provides a gauranteed analysis.

Growing medium components can also contribute some micronutrients to the system. As these materials breakdown their mineral content becomes available for plant uptake. However, these levels are so low additional sources are generally required. 
Growers frequently overlook their water supply as a micronutrient source. Much of the water in Texas, and throughout the Southwest, contains appreciable amounts of B, Cl, Cu, Fe, Mn, etc. A current water analysis is very important in designing a micronutrient fertility regime (see page 2 for details on how to get your water tested).

Using results from the water analysis and based on the type of N,P,K fertilizer used, growers can determine what micronutrient sources, and the amount that will be most effective in providing optimum nutritional levels. Table 1 presents some of the more common micronutrient sources and recommended levels.

Alkalinity and pH influence the availability of micronutrients in the growing medium. As acidity/pH goes down the availability of B, Cl, Cu, Fe, Mn and Zn increases. Although not all growers and researchers agree, a pH range of 5.5 - 6.5 generally provides optimum micronutrient availability.

The pH of a nutrient solution is also important. Since fertilizers are usually concentrated 100 to 200 times in the stock tank, excessively high pH/alkalinity can cause precipitation. If you notice large amounts of sludge developing on the bottom of the tank you may have a serious pH problem. Figure 1 provides some more specific information on the effect of pH on nutrient availability. 

Most growers that experience chronic micronutrient deficiencies are usually dealing with a pH/alkalinity problem. Be sure to address the problem (high pH/alkalinity) and not just the symptom (chlorosis, stunted growth, etc.).
Growing Media and pH

Although most growers are familiar with pH, few realize how complex this property really is. In general, the term pH refers to the acidity/alkalinity of a growing medium. However, these factors also influence the availability of many nutrient elements as well as physiological responses within the plant. The following information reviews the basic concepts of pH and their practical implications.

Acidity and pH
Acids, when mixed with water, dissociate or ionize into hydrogen ions (H+) and associated anions. The stronger the acid, the greater the amount of ionization. Those H+ ions which dissociate are measured as active acidity, while those capable of dissociating are measured as potential acidity. The sum of the concentrations of active and potential acidities yields total acidity.
H2SO4 a Ionization a 2H + SO4-
Sulfuric Acid H+Ions Anions
Dissociation of Sulfuric acid into H+ and associated SO- anion. 

In strong acids, the activity of H+ ions is so nearly equal to the concentration of total acidity that there is little need for separate designations. However, many weak acids dissociate to less than one percent, in which case a measure of total acidity gives no indication of active acidity. With extremely weak acids, H+ ion activity is generally stated in terms of the logarithm of the reciprocal of hydrogen ion activity or pH.

Factors Affecting the Determination of pH in Soilless Growing Media
Although pH may be determined colorimetrically, the most accurate and widely used method is by means of glass electrode potentiometer. Glass electrodes are unaffected by oxidizing and reducing substances, and do not liberate dissolved gases from the system. However, pH measurements have been found to vary depending upon the method of sample preparation. The principle sources of this variation include: drying, water content of the medium, and soluble salt concentrations.

Measurements made under saturated conditions may be considered the most valid in evaluating the existing environment of the growing media. However, the drying process may hasten certain chemical reactions resulting in samples near equilibrium.

Several dilution ratios have been recommended for the determination of pH. These range from the moisture saturation percentage to 1:10 substrate:solution ratio. Wider dilutions generally require longer equilibration time (30 to 60 minutes) and should be read within 60 seconds of electrode immersion.

Generally speaking, most pH determinations on soilless growing media are made using a 1:2 or 1:5 substrate:solution ratio. Stirring the suspension is necessary to keep the growing media suspended during the pH measurement.

pH measured with a glass electrode potentiometer is conducted by placing a suspension of media in contact with the glass electrode. Since dolloids behave as weak acids, the presence of a solid phase may be expected to give lower pH values when in contact with the electrode. Conversely, as the suspension becomes more dilute, pH values tend to increase.

To obtain an accurate evaluation of acidity, the presence of soluble salts should be accounted for. Salts influence ionic activities, and therefore, reduce pH values. This salt effect may be overcome by leaching with distilled water and then conducting pH determination on the salt-free sample.

Another method of masking the acidifying effects of soluble salts is to suspend the sample in a salt solution rather than water (i.e. CaCl2). Differences in pH are measured in the added-salt solution suspension. This is a more precise evaluation of acidity than that measured in a substrate water suspension. 

Determining pH in Soilless Growing Media
Several techniques have been developed for the determination of pH. However, at present, no testing standards exist for soilless growing media. The following steps outline a procedure which is used by many growers and labs throughout Texas and the U.S.

1. Collect Sample - Be sure to collect a sample which is representative of the entire mass of growing media in question. Many samples may be pulled and then combined into a representative number of "composite" samples. Remember that variation may exist between locations in the greenhouse, individual pots, as well as, different locations within the same pot. Core samples are excellent for accounting for this type of variation. Avoid taking only the top inch or so of media. This is generally where soluble salts accumulate.

2. Dry the Sample - Spread samples on a paper towel or clean surface. Allow them to air dry to a uniform consistency (this may take several days). Do not allow samples to dry to a fine powder. This will result in samples that are difficult to re-wet.

3. Mix Media and Water - Take 1/4 cup of dried growing media and add either 1/2 cup (1:2 v/v) or 1-1/4 (1:5) of distilled water. Mix thoroughly and allow to equilibrate for approximately 1 hour. If this suspension is left longer before determination, be sure and cover to prevent evaporation. (NOTE - Be sure to keep distilled water bottle closed as water will become acid over a period of time if left open.)

4. Determine pH - Using a caliormated pH meter, immerse the electrode in the suspension while stirring. Allow measurement to stabilize for approximately 1-3 minutes. 

Interpreting pH Values
Nutrient availability is largely determined by the pH of a growing medium. This is primarily influenced by the effect of H+ ions on the exchange complex as well as the solubility of various nutrient elements.

Some nutrients such as iron and other micronutrients have been found to be more soluble at low pH values. However, many other essential elements are rendered insoluble at a pH below 4.5. To maximize plant growth, it is essential to achieve a pH which will optimize the availability of all essential elements. Table 1 presents a range of pH values for soilless media with an evaluation of their effect on plant growth. 

Table 1. An Evaluation of pH for Soilless Growing Media

Extremely low 4.5 or less
Very low 4.6 - 4.7
Low 4.8 - 4.9
Slightly low 5.0 - 5.1
Optimum 5.2 - 5.5
Slightly high 5.6 - 5.8
High 5.9 - 6.3
Very high 6.4 - 6.8
Extremely high 6.9 and higher

The interpretation of pH values must be based on the technique used in the determination. The type of growing media and crop must also be considered. Growers must be extremely careful in relating pH values from soil labs or other independent testing facilities to their own operation. In general, it is best for growers to do their own evaluation to insure consistency in the interpretation of pH values in relationship to plant growth.

Modifying pH
Since greenhouse crops are generally produced in mostly organic, acid media, growers are most frequently concerned with methods of raising PH. Ground limestone (calcium carbonate) is the most commonly used material for this purpose. The activity of calcium carbonate is determined by its purity, as well as partial size. Together these factors may be used to calculate a calcium carbonate equivalent (CCE).

Hydrated lime (calcium hydroxide) is another material which may be used for the rapid reduction of pH. However, this material contributes more ions to the soluble salt content of the media than ground limestone. Generally speaking, the amount of hydrated lime used is reduced by 1/3-1/2 of the quantity of ground limestone used.

The most preferred material for raising pH is dolomitic lime (a calcium/magnesium carbonate). This material reacts much the same as calcium carbonate but also supplies magnesium for plant growth. This is particularly important where magnesium is not included in the liquid or granular fertilization programs.

The amount of these materials to use per cubic yard of growing media is based on the CCE, cation exchange capacity and existing pH of the media. Since most of these values are not available for soilless growing media, it is virtually impossible to precisely calculate how much material to add to achieve a desired pH. Generally speaking, growers use between 2-8 pounds of dolomitic lime/cubic yard of media to adequately buffer pH. However, the only way to be sure is through a trial and error procedure.

In cases where
pH needs to be lowered, agricultural sulfur or flowers of sulfur (60 mesh) may be used. The change in pH that sulfur produces is relatively slow because bacteria are required for the conversion to sulfur dioxide then to sulfuric acid.
Managing Soluble Salts

The presence of excessive soluble salts is perhaps the most limiting factor in the production of greenhouse crops. Generally speaking salt accumulations result from the use of poor quality irrigation water, over fertilization or growing media with an inherently high salt content. Although soluble salts can inhibit plant growth, when managed properly their effects may be reduced.

Salt Injury to Plants
Plant injury resulting from excessive soluble salts may first occur as a mild chlorosis of the foliage, later progressing to a necrosis of leaf tips and margins. This type of injury is largely attributed to the mobility of soluble salts within the plant. As these salts are rapidly translocated throughout the plant, they accumulate at the leaf tips and margins. Once the salts reach a toxic level they cause the characteristic "burn" associated with excessive salts.

Roots may also be injured by the presence of soluble salts. This often pre-disposes the plant to a wide range of root diseases (i.e., phythium, fusarium, etc.). Extreme injury may also interfere with water uptake and result in excessive wilting of the plant. It is extremely important to inspect the root systems of plants on a regular basis in order to monitor the effects of soluble salts.

Irrigation Water
Irrigation water is a major contributor of soluble salts to the growing medium. These occur primarily as salts of Na, Ca and Mg, although others may be present.

Soluble salts in irrigation water are measured in terms of electrical conductivity (EC). The higher the salt content the greater the EC. In general EC values exceeding 2.0 millimhos/cc are considered detrimental to plant growth. Water quality should be monitored on a frequent basis in order to avoid potential problems from soluble salts.

Fertilizers
Fertilizers are forms of salts and therefore contribute to the total soluble salt content of the growing medium. Depending on the inherent salt content of the irrigation water used, fertility levels must be adjusted to avoid salt accumulations.

Fertilizers are often classified by the amount of total salts they contain. This "salt index" can be used to determine the amount of salts contributed to the growing medium. Table 1 presents the salt index of a number of commonly used fertilizers.

Growing Media
Growing media can be formulated from a variety of components. These include peat, perlite, vermiculite, pine bark and others. Generally speaking these materials do not contain excessive quantities of soluble salts. However it is important to monitor the quality of media components carefully.

In some cases it is necessary to thoroughly leach a medium before using it. This is particularly important for seed germination and other forms of propagation. Leaching may be accomplished by running water through individual pots or trays prior to planting or by leaching the entire volume of bulk medium.

For a quantitative evaluation of this process the electrical conductivity of the leachate may be evaluated. When the EC is less than 2.0 millimhos the medium is free of excessive salts.

Managing Soluble Salts
Managing soluble salts involves an integrated approach to production. This includes the type of growing medium used, irrigation frequency, water quality, fertility regime and plant tolerance.

Growing media should contain a substantial quantity of large pores to facilitate good drainage. Media with these characteristics are easily leached and reduce the potential for the accumulation of soluble salts. When irrigating this medium it is important to apply enough water to allow sufficient quantities to leach through the container. Approximately 15-20% more water than the container can hold should be applied at each irrigation if the salt hazard is high. Water pressure must be adjusted to avoid overflow.

Since the concentration of soluble salts in plant tissues increases as moisture levels decrease, it is important to monitor the water content of the growing medium. In the presence of excessive soluble salts, growing media should not be allowed to dry out. Maintaining adequate moisture levels can be difficult in porous growing media and requires careful attention.

Providing adequate fertility is important in maintaining optimum plant growth. However if fertility levels are too high injury from soluble salts may occur. Determining the amount of nutrients to use must be based on the quality of irrigation water as well as the fertilizer's salt index. Generally most fertility regimes used for the production of potted greenhouse crops are between 150 and 350 ppm (N). Higher levels of fertility create a much greater potential for injury from soluble salts.

Perhaps the most effective means of managing soluble salts is to avoid producing salt sensitive plants. Each plant species has a distinct response to salt accumulations and growers often can select those with tolerance. Among the plants with a known susceptibility to soluble salts are chlorophytum, African violets, calceolaria, chrysanthemums, geraniums and petunias.

Table 1. Relative salt index for several fertilizers.

Fertilizer Salt index
Sodium nitrate 100
Potassium chloride 116
Ammonium nitrate 105
Urea 75
Potassium nitrate 74
Ammonium sulfate 69
Calcium nitrate 53
Magnesium sulfate 44
Diammonium phosphate 34
Concentrated superphosphate 10
Gypsum 5

Sodium nitrate was arbitrarily set at 100. The lower the index value the smaller the contribution the fertilizer makes to the level of soluble salts.
Calculating Parts Per Million

Greenhouse growers frequently express the concentration of fertilizers, in terms of parts per million (ppm). This unit of measure is relatively unique to the greenhouse industry and often there is some confusion on how ppm is calculated. The following is a "simplified" formula suitable for most greenhouse applications. 

I. To calculate the ppm contained in 1 ounce of material first solve for B:
A x 75 = B
Where:
A = the % active ingredient (AI) in the fertilizer 
B = ppm contained in 1 ounce of the material in 100 gallons of water
Example: Calcium nitrate contains 15% N (0.15 x 75 = 11.25). If 1 ounce of calcium nitrate is dissolved in 100 gallons of water the solution will contain approximately 11.25 ppm N.
II. To calculate the number of ounces of material required to make up a desired ppm concentration solve for C:
C = Desired ppm conc. / B
Where:
B = ppm contained in 1 ounce of the material in 100 gallons of water (from above).
C = number of ounces of material to add to 100 gallons of water to achieve the desired concentration.
Example: To make up a 250 ppm solution of calcium nitrate first multiply the AI x 75 (.15 x 75 = 11.25). Next divide the desired concentration by 11.25 (250/11.25 = 22). To make up a 250 ppm solution of calcium nitrate you would add 22 ounces to 100 gallons of water.
Practical Examples
I. Make up a nutrient solution of 300 ppm N. Half of the N to be supplied by ammonium nitrate, half by calcium nitrate. (Ammonium nitrate = 33% N, Calcium nitrate = 15% N).
.33 x 75 = 29.75 
.15 x 75 = 11.25

150/29.75 = 5 150/11.25 = 13

To make up a 300 ppm nutrient solution of 1/2 ammonium nitrate and 1/2 calcium nitrate dilute 5 and 13 ounces respectively in 100 gallons of water.

II. Make up a 200 ppm solution of ammonium nitrate for use with a 1:100 proportioner.

.33 x 75 = 29.75

200/29.75= 7 ounces of ammonium
7 x 100 = 700 to adjust for proportioner

To make up a 200 ppm solution of ammonium nitrate for use with a 1:100 proportion dilute 700 ounces of material in 100 gallons of water.

Selecting Your Poinsettia

The plant you choose should have dark green foliage. fallen yet low or damaged leaves indicate poor handling or fertilization, lack of water or a root disease problem. The colorful flower bracts (red, pink, white or bi-color pink and white) Should be in proportion to the plant and pot size. Little or no pollen should be showing oil the actual flowers (those red or green button-like parts in the center of the colorful bracts).
Christmas Care
Be sure the plant is well wrapped when you take it outside on your trip home because exposure to low temperatures for even a short time can injure leaves and bracts. Unwrap the plant as soon as possible because the petioles (stems of the leaves and bracts) can droop and twist if the plant is left wrapped for too long.

For maximum plant life, place your poinsettia near a sunny window Or Some other well-lighted areas Do not let any part of the plant touch cold window panes. Poinsettias are tropical plants and are usually grown at temperatures between 60 and 70 degrees F in greenhouses, so this temperature range ill the home is best for long plant life. High temperatures will shorten the file of the bracts Poinsettias do no[ tolerate warm or cold drafts so keep them away from radiators, air registers, and fans as well as open windows or doors. Place your poinsettia in a cooler room at night (55 to 60 degrees F is ideal) to extend the blooming time.

Examine the soil daily and water only when it feels dry. Always water enough to soak the soil to the bottom of the pot and discard the excess water. If you don't water enough, the plant will wilt mid the lower leaves will drop. If you water too much the lower leaves will yellow and then drop. If you keep your plant for several months, apply a soluble houseplant fertilizer, once or twice a month according to the manufacturers recommendations.

Reflowering

If you plan on saving your poinsettia and reflowering it next year, follow the procedure explained below and illustrated below.

Late Winter and Early Spring Care

Poinsettias have long-lasting flowers - their bracts will remain showy for several months. During this time, side shoots will develop below the bracts and grow up above the old flowering stems. To have a well-shaped plant for the following year, you need to cut each of the old flowering stems or branches back to 4 to 6 inches in height. Leave one to three leaves on each of the old stems or branches - new ,growth comes from buds located in the leaf axils. Cutting the plant back will cause the buds to grow and develop. This cutting back is usually done in February or early March. Keep the plant in I a sunny window at a temperature between 60 and 70 degrees F and water as described above. Fertilize as needed every 2 weeks.

Late Spring and Summer Care

If the plant is too large for the old pot, repot it into a larger pot. Any of he common peat moss and vermiculite/perlite potting soils sold at garden centers are satisfactory and easy to use. If you want to prepare your own growing medium, use 2 parts sterilized garden soil, I part peat moss and I part sand vermiculite or perlite plus I tablespoon of superphosphate per, pot and thoroughly mix.

After the danger of spring frost is past and night temperatures exceed 50 degrees F, sink the poinsettia pot to the rim in the ground in a well-drained, slightly shaded spot outdoors. Remember that the plant may need to be watered more frequently than the rest of your garden. Between 15 and August 1, prune all shoots to about 4 inches, leaving about one, to three leaves on each shoot and fertilize.

Fall Care

Take your poinsettia plant indoors at night well before the first frost (usually about September 15 in lower Michigan) to avoid chilling injury (this occurs when temperatures are below 45 degrees F for an extended period). The poinsettia can be placed back outdoors in the daytime when temperatures are warm enough or in a sunny window. Fertilize every 2 weeks To reflower your poinsettia, you must keep the plant in complete darkness between 5 p.m. and 8 a.m. daily from the end of September until color shows in the bracts (early to mid-December). The temperature should remain between 60 and 70 degrees F. Night temperatures above 70 to 75 degrees F may delay or prevent flowering. If you follow this procedure the poinsettia will flower for Christmas.

GROWTH CYCLE OF THE POINSETTIA

                 DECEMBER                                                 FEBRUARY                                                   MARCH 









                  Full Bloom.                                          Flower fades.  Lateral growth starts.                                 






























                                                  Max-Fan

What makes a Max-Fan better?

- Extremely energy efficient- Lower life time cost- Light Weight- Airtight housing- Easy installation- Quiet

- Internal parts optimized for aerodynamic efficiency

Do Can-Fans and Max-Fan use brushless motors?
Yes. The Can-Fans and Max-Fans use a brushless motor in their operation.

Are your fans Speed Controllable?
YES. Both the Can-Fan and the Max-Fan line of fans are speed controllable, DO NOT SET THE SPEED OR MOTOR CONTROL BELOW 40% OPERATING SPEED TO AVOID OVERHEATING THE FAN.

 The Max-Fan 12" is not conventionally speed controlled, The Max-Fan 12" requires the Can-Troll Speed control. 

 This control provides absolutely no motor hum when controlling the fan, it also gives you the option to control the voltage entering your fan, with an easy to use dial you can go from 1v to 130V with a turn of your hand, no matter what voltage you run, your fan will not hum!

Why did my fan shut off?

Can-Fans and Max-Fans are thermally protected. DO NOT SET THE SPEED OR MOTOR CONTROL BELOW 40% OPERATING SPEED TO AVOID OVERHEATING THE FAN.

FILTERS:
How do I size the proper fan to a filter?   The formula for sizing a room: Length x Width x Height   Divided by 3
Gives minimum recommended fan CFM
Match fan to filter
Ex.) 10ft x 10ft x 20ft = 2000 Cubic Feet     2000 Cu.ft / 3 = 667 CFM    667 CFM fan is Minimum fan size for this size area
after establishing fan size, match it to appropriate sized filter. IE, Can-100

How much CFM loss is there through the filter?

Every different size of filter provides a different resistance to each different size and style of fan you put on it, a filter at the maximum exhaust CFM rating has approximately 0.7 wg. pressure drop

All Fans will have a lower CFM at a higher pressure.

For Example at .5"wg

The 10" Max-Fan goes from 1019 CFM to 885 CFM,

The 12" Max-Fan would go from 1708 CFM to 1595 CFM

How much CFM is lost through a 25ft. Section of ducting?

Approximately 3%(Straight hard cast) to 7%(Flex Ducting)

1% to 4%  Additional loss for every 90° Bend

Where is your Can-Filters and Fans manufactured?

The Can-Filters are manufactured in Beautiful British Columbia, Canada/North America

The Fans are manufactured in Germany.

What is the difference between 38-Special Can-Filter and an Original Can-Filter?

The only difference is the carbon bed thickness

38 special = 2" Carbon bed

Original Can-Filter = 2.5" Carbon bed

38-Special expected life = Approx. 1 year

Original Can Filter = Approx. 1.5 Years

Do I need to replace the pre-filter?

It is a good idea to replace the pre-filter when they become dirty because the pre filter is blocking larger dirt and dust particles from getting into the pore structure of the carbon, a dirty pre filter increases the pressure, which will decrease the flow through the filter.

Can my Filter be refilled?

Technically the filter can be re-filled, but it is not agood idea to self-fill the filters at all, the reason for this is that Can-Filters uses an industrial shaker with timed intervals and a dust extraction system, to ensure a packed carbon bed .This eliminates the possibility of preferred air channels through the filter, because as we all know, air does not wait in line to go through a filter it finds the path of least resistance and crowds in. So if you tried packing the filter yourself, as soon as you got it as full as you think you could get it, attached a fan and turned it on, the fan would vibrate the carbon, and over time the carbon would settle and you would be left with air gaps all over the place presenting the air with channels to flow through the filter and possibly leave untreated.

What is the Maximum Temperature/Humidity I can run my filter at?

The maximum recommended temperature that you can run your filter at is 80°C / 176°F

Above 70% humidity the water molecules in the air start to get stuck in the carbon pore structure and slowly diminish the life of the filter.

How long does the filter last?

The life of a filter is determined by the concentration of the contaminant, the relative humidity and the volume of air cleaned. Unfortunately there is no indicator light on the filter that tells you when it is ready to be replaced. Experience with one Can-Filter will give you an expectation for future Can-Filters in your particular application. 

Is it recommended to push or pull through the filter?

It is recommended to pull air through the filter, the reason for this is because the filters utilize the most surface area of carbon to clean the air and you use the most of the pre filter to block dirt and debris from entering your carbon pore structure. Another advantage of pulling air through the filter is that your going to have clean air running through your fan instead of air possibly laden with VOC’s, dust, and other airborne particles that could stick to the fan blades and create air resistance.

What is the Can-Filters packed bed design?

During the manufacturing process Can filters uses an industrial shaker to vibrate the filter to ensure the carbon bed is packed tight and full to the top. This process eliminates any preferential channels which would allow the odor to pass through the carbon without the proper contact time.

Can filters only uses quality activated carbon that is designed for our manufacturing process.

The CFG packed bed design filter ensures the highest quality odor control.

What are some other applications for my Can-Filter?

- VOC Removal         -Waste Disposal - Greenhouses         -Hospitals - Manufacturing       -Schools

- Cleanrooms          -Washrooms  - Kitchens            -Paint Booths  - Pollution Control   -AirPorts

- Laboratories        -Fabrication     - Locker Rooms

When Air cooling lights, should you push or pull your airflow?

We recommend to push the air through your air cooled lights to avoid overheating your fan and to create a positive air pressure in your ducting and light hoods.

Approximately 150 - 200 CFM is required to air cool a 1000W Bulb.

What is the warranty on your filters and fans?

We warranty our fans for 5 years. Filters are warranted only against manufacturing defects.

Basic Fan & Filter Assembly:

Technical / Installation

How do I install a flange?

To install the flange to the filter- take the flange and gasket tape with screws included out of the package, fasten the foam gasket tape to the underside of the flange by removing the sticky tape. The tape will fit around the circumference of the bottom of the flange closer to the inside edge.Once the gasket tape is installed, center the flange on top of the filter. Use the 6 teck screws to fasten the flange to the top of the filter in a star pattern. Be sure not to torque the screws too much as air will pass through the gaps. We also have instructional videos of:

How to set up your new Can filter

OR

How to install the 8 and 10 inch Max Fan

Troubleshooting:

- Avoid over tightening the mounting bracket on your 8" Max-Fan to prevent fan blade rubbing

- Avoid exceeding the fans maximum temperature rating to prevent thermal protection from tripping and de-energizing fan.

- Ensure you have at least a 1" clearance around circumference of your Can-Filter to guarantee equal air distribution.

- Keep fingers and hands away from fan blades.

- To ensure maximum lifetime from your Filters and Fans, keep environment free of dust and debris buildup.


House and Garden Soil Feed Chart    


House and Garden Aqua/Coco Chart    


House and Garden One Part Chart 

Tachnaflora   Feeding Chart            


 


        


 


   


  



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Nectar of the gods: Poseidonzime, Hygeia’s Hydration, Pegasus Potion
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