Do It Yourself Hydroponic Feeding Recipes
Most hydroponic formulas are purchased in 1 to 3 parts. They will work fine when used at the recommended rate. When powdered fertilizers are mixed, it is possible to save lots of money. Here are a few formulas using basic fertilizer salts.
1. Calcium nitrate: add 11/2 grams per liter (quart) or 11/2 teaspoons per gallon (dissolved in 1/2 to 1 liter of warm water before adding to reservoir).
2. Potassium phosphate: 1/3-gram per liter (quart) or 1/4-teaspoon per gallon (dissolved in 1/2 to 1 liter of warm water before adding to reservoir).
3. Potassium sulphate: 1/3-gram per liter (quart) or 1/6-teaspoon per gallon (dissolved in 1/2 to 1 liter of warm water before adding to reservoir).
4. Magnesium sulphate: (Epsom salts): 1/4 to 1/2-gram per liter (quart) or 1/4-teaspoon per gallon (dissolved in 1/2 to 1 liter of warm water before adding to reservoir). Note: 2 to 4 can be dissolved together.
5. Chelated trace elements: 1/10-teaspoon per gallon = 1/2-teaspoon per 5 gallons (dissolved separately in warm water). Kelp, or kelp and a mineral powder, can be used in place of chelated trace elements.
This solution mixture will be dumped into a reservoir and the concentration will read around 1,300PPM on a TDS meter. In most cases, the solution should always fall between 1,000PPM and 1,500 PPM, unless medium is being flushed with dilute solution (i.e. 800PPM) or with plain water (very briefly) to remove salts. The pH should be adjusted to fall between 6.0 and 6.6.
Option: Seaweed products, humic acid, and vitamin B-1 may be added in small quantities. The PPM should be no higher than 1,500 if other products are added.
pH buffered fertilizers are very user friendly. However, the dirt cheap formulas below are much cheaper to make using basic fertilizer salts. Like traditional hydroponic farmers, making homemade plant food is the major way to save money after a grow room is up and running.
1. Calcium nitrate: add 1-gram per liter (quart) or 1-teaspoon per gallon (dissolved in 1/2 to 1 liter of warm water before adding to reservoir). During late flowering, the calcium nitrate can be lowered to 1/2 to 1-gram per liter.
2. Potassium phosphate: 2/3-gram per liter (quart) or 1/2-teaspoon per gallon (dissolved in 1/2 to 1 liter of warm water before adding to reservoir).
3. Potassium sulphate: 1/5 to 1/4-gram per liter (quart) or 1/8-teaspoon per gallon (dissolved in 1/2 to 1 liter of warm water before adding to reservoir).
4. Magnesium sulphate (Epsom salts): 1/4 to 1/2-gram per liter (quart) or 1/4-teaspoon per gallon (dissolved in 1/2 to 1 liter of warm water before adding to reservoir). Note: 2 to 4 can be dissolved together.
5. Chelated trace elements: 1/10-teaspoon per gallon or 1/2-teaspoon per 5 gallons (dissolved in 1/2 to 1 liter of warm water before adding to reservoir). Kelp, or kelp and a mineral powder can be used in place of chelated trace elements.
When a meter is used to read the PPM, it will read 1,300 PPM if the tap water had less than 100 PPM. If the tap water was something like 200 PPM, then the meter would read 1,500 PPM
The water pH should be adjusted to always lie between 5.5 and 6.3.
Some growers like to customize their formulas by adding products like liquid kelp, humic acid, and vitamin b-1.
The formulas in this section are designed for mediums that drain well such as perlite, coconut fibers, and clay pellets. These formulas will also work fine for soilless mix such as Sunshine Mix and Jiffy Mix. These have been formulated to give flowering plants all the necessary primary and secondary elements, as well as the trace elements necessary for vigorous growth. No salts will accumulate with the organic ingredients, thus providing a better tasting smoke with the end product. If quality is an issue and so is volume, the following sample formulas are definitely worth a try.
For complete control, cheap and light perlite is recommended for the medium because it does not alter the solution’s pH and fertilizers do not cling to it. Perlite also allows lots of air to get in the spaces when solution drains through it. However, perlite needs regular irrigation, such as a few waterings a day, or continuous irrigation. Not for the sake of food necessity, but for the fact that dry perlite sends out a dust. This dust can collect on the top of leaves.
Clay is good medium, but it is heavy and a little expensive. It is negatively charged and will hold some positive ions such as calcium and potassium. All mediums can be flushed with plain water—or low PPM—regularly. For example, a grower can feed for 6 days and flush once a week during veg and flower.
Materials such as clay that alter the pH can be of use to keep the pH down. Also, holding some water and nutrients can be good too, especially between feedings when the water is drained from the growing medium.
Any recommended rate from an organic fertilizer manufacturer should work fine. Feeding needs to be more precise during bloom. If chemicals are used during vegetative growth, and organics are used during bloom, nobody will be able to tell the difference from a garden grown only with organics. This is a way to make tasty produce on a skinny budget.
Vegetative Growth Formula A
Manufacturer’s recommended rate for Sea Mix 3-2-2, or two-thirds of the recommended rate for Alaska Fish Fertilizer, combined with the recommended rate for liquid kelp. In addition, pH up or pH down can be added until the pH is between 6.0 and 6.5. Adding Epsom salts (magnesium sulphate), 1/2 to 1-teaspoon per 5 gallons will help combat magnesium and sulphur deficiencies.
Special note: All pH testing and addition of a pH up or pH down is optional, although recommended. Hydrogen peroxide usage at 1 to 3 ml / gallon is recommended to keep the medium clean.
Vegetative Growth Formula B
When it comes time for the second feeding, the fertilizing can be repeated. Here is an optional solution to use: Sea Mix, two-thirds of the manufacturer’s recommended rate. Humic acid (made from organic molecules created from the breakdown of organic matter) at 1/5 to 2/3 of the recommended rate. Add pH up or pH down until the pH hits 6.0 to 6.5.
Vegetative Growth Formula C
Earth Juice or Meta Naturals products applied at the recommended rate.
A grower can take any commercial fertilizer and mix it at the recommended rate and results will be fine, but in order to grow specific plants productively and with the lowest cost, making custom formulations is the way to go. All big-scale farms know the importance of making their own fertilizers, which is a major expense once the farm is set up.
After the grower can acquire the necessary components to make a custom blend, the next step is to mix a simple mixture.
During flowering, a grower cannot afford to be sloppy. Feeding is more critical and plants use more nutrients when they are producing flowers. Here are some sample formulas for this important stage of growth.
Bloom Formula A
1. Four teaspoons per gallon of Earth Juice Bloom.
2. Four teaspoons per gallon of Earth Juice Grow.
3. Four teaspoons of bat guano per gallon. Guano should be placed into a teabag or added directly into the tank. Bat guano can cause stomach aches when it is used in a recirculating hydroponic system, even with minimal exposure. For that reason, using the replacement (potassium phosphate) from the chemical cheat sheet (below) is safer than using bat guano. Or, more organically, using more Greenfire Earth Juice Bloom is another option.
4. Growth Plus (Nitrozyme) at 1/2-teaspoon per gallon
5. Epsom salts (magnesium sulphate) at 1/2 to 1-gram per quart (liter). Epsom salts should be dissolved in warm water, before adding to nutrient solution.
6. One-gram per gallon of sulphate of potash (potassium sulphate) or 2 grams per quart (liter) of wood ashes. Sulphate of potash should be mixed separately in hot water for it to completely dissolve.
7. Finally, pH is adjusted to 5.5 to 6.5 with natural pH up or pH down.
Options: A grower can add the following to the above formula before adjusting PH.
1. Humic acid at 1-teaspoon per gallon or at 1/4 to 1/3 the recommended rate.
2. For other trace minerals, a grower can add half to full recommended rate of liquid kelp.
3. Adding 1 tablespoon of molasses and 2 teaspoons of yeast into 1 quart (liter) is a cheap homemade catalyst. The mixture should be dissolved before it is added to the tank. It will add enzymes and help to combat upward pH drift.
The Bloom Formula solution should sit one or two nights so that pH stabilizes. Running a pump in the solution can help keep the solution agitated. Sometimes, some of the materials will flow to the bottom, such as bat guano, but most of this formula will stay nicely mixed. The pH of this solution will drift less upward the longer it sits in the nutrient tank. The pH should be monitored daily and adjusted to between 5.5 and 6.5, using either a natural pH up or a natural pH down.
Chemical Cheat Sheet
1. 1/2 to 1-gram of calcium nitrate can be used instead of Earth Juice Grow and Earth Juice Bloom.
2. A grower can use chelated trace minerals (1/2-teaspoon for every 5 gallons) while canceling the usage of Growth Plus (Nitrozyme) and Pyro Clay.
3. Using potassium phosphate at 1/2 to 3/4-gram per quart (liter) allows a grower to eliminate the bat guano. The potassium levels can be changed during various stages of bloom to accommodate phosphorous levels.
Bloom Formula B
1. Four grams per quart (liter) of Pure Earthworm castings. Worm castings can be wrapped in panty hose, a teabag, or cheesecloth. Squeezing the castings in the bag periodically helps to release the fertilizer more quickly.
2. Four teaspoons per gallon of Earth Juice Bloom.
3. Four teaspoons of bat guano per gallon. Guano can be put in a teabag or panty hose. Guano should be squeezed periodically to release the fertilizer. (Warning: A formula with bat guano that is re-circulated may cause stomach aches.)
4. Growth Plus (Nitrozyme) at 1-teaspoon per gallon.
5. Epsom salts (magnesium sulphate) at 1/2 to 1-gram per quart (liter). Epsom salts should be dissolved in warm water before adding them to a nutrient solution.
6. One-gram per gallon of sulphate of potash (potassium sulphate) or 2 grams per quart (liter) of wood ashes. Sulphate of potash should be mixed separately in hot water to completely dissolve the crystals before adding them to the nutrient solution.
The pH should be checked daily and adjusted to 5.5 to 6.5. A lower number is better for an upward drifting pH.
1. Pyro Clay can be added at 1-gram per liter.
2. Humic acid can be added at 1-teaspoon per gallon or at 1/4 to 1/3 the recommended rate.
3. For other trace minerals, add half to full recommended rate of liquid kelp.
4. Adding 1 tablespoon of molasses and two teaspoons of yeast into 1 quart (liter) works as a catalyst. The mixture should be dissolved before it is added to the tank. The mixture will add enzymes and help combat upward pH drift.
Chemical Cheat Sheet
The first two substitutions must be made.
1. A grower may use 1/2 to 1-gram of calcium nitrate and the worm castings and Earth Juice Bloom can be eliminated from the original recipe.
2. Potassium phosphate at 1/2 to 3/4-gram per quart (liter) can be added instead of bat guano. The potassium levels can be changed during various stages of bloom to accommodate phosphorous levels.
3. Using chelated trace minerals (1/2-teaspoon for every 5 gallons) can cancel the usage of Growth Plus (Nitrozyme) and Pyro Clay.
Special Notes—for All Organic Hydroponic Formulas
Solution should be topped up regularly (i.e. daily to weekly) with plain water or nutrient solution, depending on how the pH, PPM, and water level changes.
The pH of the solution should be checked and modified after adding liquid to the reservoir. Drawing a top-up line in the reservoir with a permanent felt-tip pen helps to make topping up the reservoir a brainless exercise. Large reservoirs that can run a few days to a week with proper pH and PPM make things even simpler.
The organic formulas I’ve given should be near 1,500PPM when read on a TDS meter after they have been mixed if the water supply reads at 0 PPM. A PPM meter can be used as a reference meter. A grower should take readings once in a while to see if the PPM goes up or down.
Growers that make a large reservoir that contains all of the nutrients and holds a constant pH and PPM until the reservoir is changed have great results. This is not the most cost effective, but it is the easiest feeding method.
If the PPM stays the same or goes down just slightly, adding the regular solution that would be used normally can allow for minimal maintenance since the pH and PPM should be at desired levels. The grower may get lucky and find that he just needs to add some more new solution to the old solution to get great results without having to dump out the old batch. This is a money saving tip.
Making a solution that keeps a constant PPM (or only slightly lowering PPM) and is pH buffered gives the plants the exact elements they need until the reservoir becomes empty is the path to feeding perfection. This is perfect gardening if a grower can know exactly what to feed his plants when the solution runs low. This is expert territory.
If the PPM goes up, more water should be added to the tank to dilute the solution. With this approach, complete changes of solution are recommended, especially for larger plants that use up more nutrient than water.
After a couple of weeks, an organic hydroponic solution can bring on odors, depending on the fertilizer (e.g. stinky bat guano).
If a PPM meter is used in an organic or chemical-organic garden, what works is changing the solution when the PPM drops to 1/3 to 1/2 of the original strength (i.e. PPM drops to 500 to 750 PPM). The waste can be poured out anywhere in an outdoor garden. Or additional amounts of the same formula can be added from time to time to replenish nutrients, if there is no smell. For the trained eye, individual nutrients can be added, such as Earth Juice Grow or bat guano, as deficiencies are spotted.
Nitrogen consumption is probably the heaviest of all the elements in the formulations.
Changing the solution and replenishing all nutrients is the best move to keep things simple.
Using pure, clean water is the easiest way to increase the yield in the garden.
The quality of an indoor water supply will vary from city to city, creek to creek, river to river, spring to spring, pond to pond, and well to well, not to mention rain water zones.
Water filters, reverse osmosis machines, distillation devices, and rainwater reservoirs are all methods of obtaining pure water. These purifying methods can be done for large and small quantities of water. Naturally, machines and filters that handle larger amounts of water will cost more.
Some machines and filters remove more dissolved solids than others. The better units normally cost more.
There are cheap filters that can be attached to faucets to remove chlorine from the water. Often, chlorine is the domestic gardener’s worst enemy.
Desalinizing sea water is an expensive option for making quality use of sea water. Prices of these units have come down over the past few years.
Adaptability to water temperature varies from strain to strain, but generally speaking, water you give your plants should have a temperature near 65 to 70°F.