My goal has been to create an easy-to-make and inexpensive hybrid “one-part” nutrient solution using a combination of “organic” and inorganic ingredients. To add to the fun, I decided to use everyday kitchen and food chemicals that I could purchase at a grocery store. Then I would try it out on a bunch of plants that I've never grown before. So how has THAT gone, Jim?
Thomas Edison said: “Results? Why, man, I have gotten lots of results! If I find 10,000 ways something won't work, I haven't failed. I am not discouraged, because every wrong attempt discarded is often a step forward.”
Yes, I put “organic” in quotes. Why is that? I have some misgivings about using the word “organic” when talking about growing, selling and consuming foodstuffs. It is more of a legal and marketing term than an agricultural term, in my opinion. There is commercial confusion toward its use, and growers and sellers are too mired down and restricted by governmental rules and regulations. There isn't even any agreement between the states as to what “organic” means, much less the USA, EU, and other countries. Like many other soil and hydroponic growers and enthusiasts, I prefer to use the term “natural.” But I hear the argument coming!
If something is “natural,” then it's counterpart must be “unnatural,” right? So your solution would have natural and unnatural ingredients! In my reckoning, natural only means that the origin was either organic: i.e. living or once-living; or anything inorganic (non-living, such as elemental salts) that occurs in nature. Any other ingredient is derived: 100% synthetic, man-made, factory / lab produced with no direct counterpart occurring in nature.
Why is this important? Take General Hydroponics, for example. I have used their three-part Flora series since I started in hydroponics. The nutrients used in the Flora series are all “salts” of elements. Nothing is those solutions is “unnatural.” They are all natural and do occur in nature. The salts may be refined, but they have a counterpart in nature. Those salts are almost identical to what is found in humans, sea water, and virtually every other living thing. Yet the government prevents General Hydroponics from calling their product “organic.” Here is a great pdf article from General Hydroponics concerning this debate. By the way, I use their products but I have no monetary or business interest in them.
Conversely, what I am experimenting with right now, by government standards, probably could not be used in any commercial hydroponic setup. They would deem the mixture “organic” because many of the ingredients are “organic.” I can commercially grow stuff and call it “organic” if I meet certain strict guidelines, but there's a good chance I can't use my hybrid “organic” nutrient solution to grow it! This is all clear as mud, right?
Back to the chemical issues of why a hybrid one-part solution is so difficult to achieve. There are numerous elements that all plants require: nitrogen-phosphorus-potassium (NPK; also known as macro-nutrients) and calcium, magnesium, sulphur, manganese, boron, iron, selenium, copper, and several other elements commonly known as micro-nutrients. Plants use these nutrients in varying amounts during their different cycles, such as vegetative growth, budding/blooming, and fruiting.
A one-part system of only inorganic elemental salts could not handle the growth cycles, hence two-and three-part solutions like the Flora series. However, it may be possible to have a one-part system if some of the macro and micro-nutrients are provided to the plant using beneficial microbes right at the roots. This will convert the nutrients directly into something the plant can use. The breakdown of the “organic” ingredients in the solution provides the food and energy for the microbes to thrive. There are companies which sell microbial “boosters” for hydroculture.
It is very hard to measure and quantify organic particles in a nutrient solution. Elemental salts can easily be measured using a good hydroponic “multimeter.” I have a Milwaukee Instruments MW 802 (here is the just-posted meter blog) which can measure pH, electrical conductivity (EC), parts-per-million (ppm), and total dissolved solids/salts (TDS). All multimeters, however, are useless for measuring the organic particles. The only way I could get an accurate assay of my dozens of experimental solutions would be to take them to a lab. I don't have that kind of money. I do have patience, however.
Instead of a lab, I have a fuzzily general knowledge of chemistry and common food ingredients and the ability to add and subtract ingredients until I get results. I use years of growth results using the three-part nutrient solution as a baseline.
Listed below are the ingredients of my latest and best solution. It has had some success in growing my plants. It has not killed or “burned” a single plant. Yet, I'm not seeing sustained growth. The plants will grow to a certain stature and thickness and then slow down to a near stop. They are full and green with no obvious issues; except for an occasional mild phosphorus deficiency in the first stages, which happened with the homebrew and the commercial three-part system, there is no stunting, wilting or yellowing, just exceptionally slow growth. Well, slow as in “soil-growing slow,” not the awesome fast growth I have been used to in hydroponics.
My theory is that the microbes at the roots are not converting enough NPK fast enough, or that I might not have some of the “right” microbes. Some converted NPK and immediate-use salts are getting into the roots through the wet-root uptake that is used in hydroponics, but microbial fixation of NPK, the preferred method of soil-based plants, is too slow for this compact system. The homebrew nutrients may work better in a larger reservoir.
Here are the ingredients that I am using and why I chose them. Your grandma and grandpa used some of these ingredients for their garden!
Knox (or other brand) unflavored plain gelatin. Gelatin, or gelatine, is a great source of bio-available nitrogen, approximately 16%. It's easily found and inexpensive. Known for years to soil growers.
TetraMin (or other brand) Tropical Fish Food Flakes. A very good source of NPK, and almost all the other elemental nutrients. It consists of mostly fish meal (which you can also buy at home and gardening stores), algal meal, and chelated ionic compounds (just call them vitamins and minerals.) It is easy to find and inexpensive. Known to soil growers. I have found little discussion among hydroponic enthusiasts.
Dark unsulphured molasses, also known as “blackstrap,” is a very good source for NPK and almost all the elemental nutrients. It's a good chelator (binds atoms in a way that plants can use), and is a carbon (food for microbes) source. Available almost anywhere. Known for years to both soil and hydroponic growers.
Magnesium sulphate, also known as “Epsom salt.” A natural ocean residue. An excellent source of magnesium and sulphur and contains a small amount of other elemental nutrients. Found almost everywhere. Known for years to soil and hydroponic growers.
Morton (or other brand) salt substitute. Many people, especially people with high blood pressure, use this as a salt substitute in food. It has potassium, phosphorus and chlorine in the form of chloride (all living things require small amounts of chlorine). I've seen very little of salt substitute use in plant growing.
Rumford (or other brand) reduced-sodium aluminum-free baking powder. It has calcium, potassium and phosphorus (from pyrophosphate; very soluble and a good chelator) and bicarbonates. The bicarbonates act as a buffer to acid. There is rice flour, and the non-GMO cornstarch in the baking powder is a type called rs, or resistant starch. It is an excellent slowly-metabolized food source for microbes. I've seen very little use of baking powder in plant growing.
Sea salt. Use it in small quantities due to the sodium; it has a trace amount of micro-nutrients. Known to soil and hydroponic growers.
Boric acid, a source of boron. The powder is available almost anywhere. It can be toxic in large quantities so handle carefully. Only a tiny pinch is needed. All living things need a trace amount of boron. Known to soil and hydroponic growers.
Iodized salt. Only a tiny pinch is needed. Virtually all living things need a trace of iodine.
Pure lemon juice. A carbon acid (organic) instead of a mineral acid. A good chelator and buffer to alkalinity. Lemon juice can help chelate ions and deliver calcium and phosphorus. Citric acid has a role in metabolic processes. Proper use of lemon juice and bicarbonate will adjust the solution pH to the required level. Known for years to soil and hydroponic growers.
A tarnished -and real- copper penny and a rusty steel bolt. I was originally boiling these items – separately; look up 'battery' and 'electrolyte'- with the solution to obtain copper carbonate/oxide and ferrous sulphate. I no longer use them. I believe the other ingredients will provide the necessary copper and iron. I saw no change by removing the objects from the formula.
I have also used parboiled rice water (many nutrients and a good chelator) and finely ground egg shells (calcium) but I felt that they were redundant and removed them.
I don't feel that I have failed; I feel that I have some small success. I'm not giving up on this quest, just temporarily putting it lower on my list of priorities. I've got that greenhouse to finish, and I'm designing an advanced hydroponic system.
I feel that I am very close. I purposely left out more details and measures so we can talk about this. This fertilizer formula is partly “organic” and 100% natural. If we can come up with something that is inexpensive and easy-to-buy locally, and it is virtually non-toxic and will feed most plants well, then we have found another way to feed ourselves and others.
I'm not sure if I'm baking a cake, making a stew, or growing vegetables! Grow, have fun, and learn.