Welcome to the BGHydro Official Hydroponics FAQ section. Use the links or search box below to find your way around.
What is NPK, how does it affect my plants, and what combinations do I need?
N – Nitrogen
Nitrogen is a unique element, as plants are able to take up nitrogen in the form of an anion (a negatively charged molecule) or a cation (a positively charged molecule). Plants are able to take up nitrogen in as NO3 or Nitrates and NH4 Ammonium. Plants require or consume more nitrates than ammonia, thus its not. A well balanced nutrient solution will have less than 10% of available nitrogen in the form of ammonia. Nitrogen has many functions in the plant; it is found in proteins, chlorophyll, protoplasm and plant hormones.
Source – All premixed nutrients will have adequate nitrogen levels. If a customer wishes to give his plants extra nitrogen in the vegetative stage then he can use Cal-Mag Plus at a rate of 1-2 teaspoons (5-10ml) per gallon. This will supply the plant with 25 – 50ppm extra nitrogen, this will be more than adequate. Using Cal-Mag will also supply the plant with extra Calcium, Magnesium and Iron. If a customer wishes to use an organic source of nitrogen then they can use Mexican Bat Guano. Note that only 1% of the 10% of nitrogen in Mexican Bat Guano is readily available to the plant, the other 9% will slowly be released over a few weeks as the organic nitrogen is broken down. Bat Guano cannot be used in NFT or aeroponic systems; it will also have a limited affect in ebb and flow and drip systems. Bat Guano is ideal for soil growers.
Deficiency – Growth is slow, sparse and spindly the older leaves turn yellow and will eventually dry out and die. The complete leaf will turn yellow, with no green veins.
Toxicity – The plants will produce excess foliage that will be dark green. The plants will also be softer, disease and insect outbreaks will be severe (this will be due to a weaker softer plant). The root system will also be underdeveloped. High nitrogen levels can also retard flowering and fruiting, decrease in yields as flowers don’t set and lower fruit quality. Nitrogen deficiency and toxicity is rear and will not be a problem if growers use premixed nutrients and follow the directions for these nutrients.
P – Phosphorus
Phosphorus is a very important nutrient for plants. It is required by seedlings, newly rooted clones and flowering and fruiting plants. Phosphorus is essential for the development of healthy roots, stimulation of flowering, ripening of fruits and seed production. Phosphorus is also required for the hydrolysis of starch to sugar and for the synthesis of starch to sugars (also known as energy transfer).
Source – Again, premix nutrients will have adequate phosphorus for general plant growth. Plants will need extra phosphorus when the plants begin flowering and fruiting. This is why growers must change from a vegetative formula to a flowering formula. The flowering formulas will have higher phosphate and potassium levels to help stimulate flowering, fruiting and seed production. This all culminates in higher yields and better tasting produce. Taste is increased because of higher synthesis of starch in to plant sugars. For a customer to really boost their yields of flowering and fruiting crops it is advisable for them to use a blooming enhancer. Bloom Booster, Monster Bloom, KoolBloom and PK13/14 are all products that will boost phosphorus and potassium levels. Bloom Blaster and Monster Bloom must be applied at a rate of 1 teaspoon (5 grams) per 5 galloons of water. Kool Bloom ¼ teaspoon per gallon or 1¼ teaspoons per 5 gallons of water. PK13/14 must be applied at a rate of 1¼ teaspoons (5ml) per gallon of water. For organic growers, in the soil, Jamaican Bat Guano can be used at a rate of 2-3 (10-15 grams) tablespoons per gallon of water.
Deficiency – Plants are stunted and the leaves turn dark green to purplish color. This is due to a buildup of Anthocyanin pigments. These symptoms occur in the older leaves first. Plant maturity will also be delayed and yields will be low. Seed production is also severely affected.
Toxicity – Phosphorus toxicity is very difficult to diagnose. Excess phosphorus will cause deficiencies of calcium, iron, copper and zinc. This will cause confusing signals as other minerals may be showing signs of deficiencies even when adequate amounts of these minerals are present.
K – Potassium
Potassium is the catalyst in plants. It is important for the manufacture and transport of plant sugars/carbohydrates, increases the chlorophyll in leaves, regulates the opening and closing of the leaf stomata and aids in disease resistance, water uptake and ripening process of fruits. Potassium is also found in the juice of fruits which contributes to an increase of fruit taste and fruit quality.
Sources – The sources of potassium are the same for Phosphorus above.
Deficiency – Symptoms occur in older leaves first with yellow blotches and in severe cases dead spots will occur. Branches and stems will weaken and eventually becomes brittle. Flowering and fruiting is diminished and yields are low and poor in quality.
Toxicity – leaf margins may burn in sever cases, but often it will effect the uptake of magnesium and magnesium deficiencies will occur.
Ca – Calcium
Calcium is as important as N, P and K. Calcium is required in the roots, stems, leaves and fruits of plants. It is found in every cell wall and is required for the absorption of nitrogen.
Sources – Most nutrient solutions will have adequate calcium for general plant growth. If a customer is using RO water then they should consider using Cal-Mag Plus. An application rate of 1-2 (5-10ml) teaspoons per gallon of water is sufficient to rectify any deficiencies.
Deficiency – Flower bud development is retarded, thus reducing yields, fruit size is decreased. Roots die, leaving the plant open to root rot attack. Young leaves show symptoms before older leaves. The leaves can be deformed, and have yellow blotches which later turns into dead spots.
Toxicity – No visual symptoms; may cause magnesium deficiency.
Mg – Magnesium
Magnesium is found in the chlorophyll molecule. If a deficiency of magnesium occurs then magnesium is transported from the lower leaves to the new leaves. Magnesium uptake is affected by the concentration of Potassium. If high levels of potassium are applied then the amount of magnesium should increase e.g. at the second week of flowering when blooming enhancers are used then Cal-Mag Plus should be applied.
Sources – Most nutrient solutions will have adequate amounts of magnesium. If a grower is using RO water then Cal-Mag Plus should be used.
Deficiency – Older leaves, lower half of the plants’ leaves show signs of yellowing. The yellowing occurs between the leaf veins which remains green.
Toxicity – There are visual symptoms for magnesium toxicity.
Si – Silicon
Accumulates mostly in the epidermal cells of a plant. It is also found in other cell walls. Silicon helps creates hardier, heavier and stronger plants. It has also been known to increase the plants resistance to fungal attacks.
Sources – Silica Blast and Pro-Tekt (both potassium silicate) and Pyrosol are the main sources of silicon. Growers should take care when using these products as they will increase the pH of the nutrient solution, thus the grower will need to add pH Down to bring the pH back to 6.
Deficiency – Deficiencies of silicon have been known to reduce yields.
Toxicity – Not known.
Nutrients are split into two formulations because the phosphorus, calcium and sulfur nutrients need to be separated from each other. If this is not done, then the calcium and phosphorus, as well as the calcium and sulfur, in high concentrations, will react with each other to form calcium phosphate (cement) and calcium sulfate (gypsum). Both calcium phosphate and calcium sulfate precipitate out of solution, forming a white precipitate (which will usually fall to the bottom of the reservoir), and are unavailable to the plants. This will cause phosphorus, calcium and sulfur deficiencies in the plant. Once these nutrients are mixed together in the reservoir they are at lower concentrations and also a pH balanced nutrient mix will prevent the three nutrients from reacting with each other. This is another reason why balancing pH is extremely important.
Some nutrients are one part such as FloraNova Grow and Bloom, are extremely thick and need to be shaken well before mixing into the reservoir. If these nutrients aren’t shaken well before use then the precipitates that have formed at the bottom of the bottle aren’t remixed into solution. This will cause deficiencies, slow growth and reduced yields.
Some nutrients also come in three parts. This is done with some brands of hobby hydroponic nutrient formulas so that the grower can mix the three parts in different ratios to create different solutions for the vegetative and bloom stages, as well as for different types of plants, without having to switch to a different product. Most commercial formulas, however, are two part (you’ll never see a commercial hydroponic farm using a one or three part nutrient formula; they are primarily for hobby growers).
There are many brands of nutrients that are available to hydroponic growers. The grower should first decide if they want to grow organically or conventionally. The type of growing medium will also determine what type of nutrient a grower should use e.g. if coco growing medium is used then you should consider using nutrients that are designed for coco (like Canna Coco nutrients). The crop stage will also determine what nutrient should be used e.g. a vegetative nutrient formula should be used when a plant is in vegetative stage (such as Super Veg A and Super Veg B) and a flowering nutrient such as Super Bloom A and Super Bloom B should be used for when the plant enters flowering. Dry nutrients tend to be a little more difficult to mix than liquid nutrients, especially if they are old, but they are also easier to use (only one part to mix) and cost less. Ultimately, the brand of nutrient which the hydroponic grower should use is purely up to the grower to decide, but BGH is always available to help you make the decision.
For soil growers, plants can be fed once every second or third watering. If plants are fed with every watering then nutrient buildup and lockup becomes a problem causing stunted growth, “crows foot” (curling downwards of the leaves), leaf burn, deficiency symptoms, burnt and damaged root system and decreased yields.
For hydroponic growers, plants can be fed with every watering. The watering cycle will depend on plant growth stage, size, room temperature, growth medium and hydroponic system. Small plants, such as seedlings and clones recently transplanted and plants in early vegetative stage, growing in rockwool, will require watering only once every 4-6 hours. As the plant grows bigger and enters flowering and fruiting then the water requirements of a plant increases. The watering cycle will then be every 2-4 hours. A grow room temperature of 80 – 90 °F will require more watering cycles per day than a grow room with a temperature of 65 – 70 °F. This is due to the higher transpiration rate of plants at higher temperatures. Hydroton Rocks and perlite require more frequent watering than coco fiber and Ready-Gro, which requires more watering cycles than rockwool. The watering duration for a drip system will be longer than for an ebb and flow system. The reason for this is that the drip system will emit water at a slow rate where as the ebb and flow system completely floods and saturates the growing medium in a few minutes. Aeroponic systems require frequent watering cycles; a burst of nutrient solution for a duration of 30-60 seconds is required every 3 to 5 minutes.
Conventionally (as well as hydroponically) grown plants grow faster and produce higher yields of higher quality. Some growers testify that organics produce better tasting crops; this may be true due to various organic components that become available to the plant during the breakdown process of organic matter. For this to be completely true the plant requires both organic plant and animal matter. For most organic nutrients, a breakdown process needs to occur for the nutrients to become available to the plant. This breakdown process is preformed by micro-organisms found in soil. These micro-organisms break down the organic matter into nitrates, ammonium, potassium oxides etc. These are exactly the same as what the conventional nutrients provide to the plants. The organic process takes time and the micro-organisms also consume some of the nutrients that the plants require. Plants grown using conventional nutrients tend to grow faster and yield more, but it’s also easier to over-fertilize plants and salt buildup can be a problem if you don’t leach periodically. Correcting deficiencies is also easier with conventional nutrients since they are so readily available to the plant. Organically-grown plants tend to grow slower and yield less, but there is less of a problem with salt buildup and flavor can often be better than conventionally-grown plants. Organic fertilizers may also limit the choice of growing mediums and systems you can use. Here are some examples of conventional (mineral) and organic nutrients that BGH supplies:
· Flora series
· Super Veg and Super Bloom
· Canna Series
· Pure Blend and Pure Blend Pro
· Earth Juice
· Age Old
Organic growers also use organic sprays for controlling leaf pests and natural predators for controlling insect pests such as white flies, aphids, spider mites and thrips. Chemical sprays produce instant results against pests and also provide residual coverage. Chemical sprays can cause bitter taste on fruits and vegetables and can be a health hazard to people. The best results are gained from a combination of both systems. Provide the plant with chemical nutrients and enhancers and use organic pest control. This will eliminate the bitter taste that chemical sprays can leave on the crop. Examples of organic pest control are:
Neem Oil – Produced from the seeds of the neem tree. It is cold pressed. Neem oil causes maturity of insect pests to be retarded, thus stopping the pests from breeding. Neem oil will not kill insects. Application rate is 1 (5ml) teaspoon per quart plus ½ (2.5ml) teaspoon of dishwashing liquid or wetting agent such as Penetrator or Coco Wet.
Pest Out – Contains clove oil, garlic oil, cottonseed oil, various acids and sugars. This product controls mites, thrips and aphids. The application rate is 3 (15ml) teaspoons per quart.
Caterpillar Killer – Contains Bacillus thuringiensis. This product controls leaf-eating caterpillars and loopers. The application rate is 1 to 2 teaspoons per gallon.
Insect Killing Soap – Contains potassium salts of fatty acids. This product controls white flies, mites and aphids.
Gnatrol – Contains Bacillus thuringiensis subsp. israelensis. This product controls fungus gnat larvae in the growing medium.
Serenade – Contains Bacillus subtilis. This product controls powdery mildew, rust, gray mold, leaf blight and other leaf fungi. It can also be applied to the root system to help control root rot. Application rate of 4 oz per gallon of spray mix. Serenade is also available in a ready-to-use spray bottle.
Mildew Cure – Contains clove oil, garlic oil, cottonseed oil, various acids and bicarbonates. This product controls powdery mildew. The Application rate is 2-3 (10 - 15 ml) teaspoons per quart.
Sulfur Burner / Vaporizor – Sulfur burners’ burn sulfur, which creates sulfur vapor. This vapor alters the pH of the leaf surface which controls powdery mildew and slows the breeding process of insects. Powdery mildew control is effective as long as the sulfur remains on the leaf. Dusting the leaves will remove the sulfur. The application of sulfur should be applied at night time when the lights are off. The room should not be disturbed by the grower or exhaust fans for 4 hours while the burner is operating. The grower should not enter the room during operation.
SM-90 – Contains coriander oil, canola oil and Triethanolamine (this is a pH buffering agent). SM-90 can be used in the root zone and as a foliar spray. Its purpose is to control fungi. In the root zone it controls root rot pathogens and on the leaves it will control powdery mildew. Apply 2-3 ml per gallon of nutrient solution for the root zone and 1 part SM-90 to 5 parts water for foliar spraying.
Hydroguard – Contains Bacillus subtillis and Bacillus amyloiquefaciens. Both these mirco-organisms suppress the development of fungi development thus controlling root rot pathogens in the root zone. Apply at a rate of 1-3 (5-15ml) teaspoons per gallon of nutrient mix. For soil gardens apply every 30-90days. For hydroponic gardens using Hydroton rock, perlite or aeroponic systems, re-inoculation should occur every 7 days, whereas coco, Ready-Gro and rockwool should be re-inoculated every 14 days.
Nutrients are stand-alone, in other words plants can be grown successfully with nutrients with out the need for enhancers. Enhancers are not stand alone. Enhancers are used in addition to nutrients and are designed for a specific task, e.g. bloom stimulation, root development, flavor, etc.
Root Stimulators – Rhizotonic, Green Fuse Root, Super Nova
Growth Stimulators – Green Fuse Grow, Floralicious Grow
Flower and Fruit stimulators – Bloom Blaster, KoolBloom, PK 13/14, Monster Bloom, Green Fuse Bloom.
Flavor – Sweet, Floralicious Bloom.
Enhancers are designed for growers to be able to get the maximum performance out of their plants. Please note that when using enhancers the pH and TDS of the nutrient solution should be closely monitored. The pH and TDS levels should always remain within the optimal range for each growth stage.
Rhizotonic – enhances root growth, thus creating more feeder roots. Rhizotonic also helps plants overcome stress such as transplant shock. For the seedling and clone stage use 3 (15ml) teaspoons per gallon. For mid and late vegetative stages use 1½ (7.5ml) teaspoons per gallon. From flowering till the end of harvest use ½ (2.5ml) teaspoon per gallon.
FulMag – enhances root development and allows better nutrient absorption by the root system. The application rate is 3 (15ml) teaspoons per gallon.
Floralicious Grow – Application rate is 1 (5ml) teaspoon per gallon from early growth stage through to late growth.
Bloom Blaster – This product should be used from the second week of flowering through to the last week before harvesting. Bloom Blaster helps stimulate the plant to produce flowers and increases fruit size and mass. The application rate is 1 (5grams) per gallon of water.
Floralicious Bloom – This taste enhancer should be used from early flowering until harvest. Application rate is 1 (5ml) teaspoon per gallon.
Sweet – This is also a flavor enhancing product, it can be used form early growth through to harvesting. Sweet can be used in the place of Floralicous Grow and Bloom.
Enhancers are highly recommended but not required with the Flora Nova series. General Hydroponics recommends using their enhancers for the Flora Nova series.
Diamond Nectar– should be used all the way through the plants life.
Flora Shield – should be used all the way through the plants life.
Floralicious Grow – for early to late vegetative stages.
KoolBloom – from late flowering to harvest.
Floralicious Bloom – from early flowering through to harvest.
Other enhancers such as PK 13\14, Monster Bloom, Bloom Blaster, FulMag, Green Fuse Grow and Bloom and Liquid Karma all can be used with the Flora Nova series.