Five things to consider when trying to copy commercial hydroponic nutrients


There are hundreds of different formulated hydroponic fertilizers out there and most of them are very expensive. Due to these very high costs, growers will often want to copy a set of hydroponic products they are very familiar with or a set of products that other growers – ideally growing under similar conditions – have had success with. However, the process of copying a commercial hydroponic nutrient with raw inputs is not as straightforward as many would like it to be and the procedure to do this accurately can be complicated due to both the nuances of the fertilizer industry and potential measures manufacturers might take to make reverse engineering of their products significantly harder. In this post I want to talk about five things you should consider before attempting to copy a hydroponic nutrient formulation, so that you can be very aware of the potential issues and problems you might find along the way.

The labels are often not accurate (enough). A fertilizer’s label contains the minimum guaranteed analysis of the fertilizer. Depending on the legislation, this usually means that the fertilizer must contain, at a minimum, this amount of every one of the specified nutrients, but there is no problem if the fertilizer contains more than what the label discloses. If a company is selling a fertilizer that has an NPK of 12-12-12 they can actually register that fertilizer as a 10-10-10 fertilizer and sell it as if it was a 10-10-10. The fertilizer will in reality be a 12-12-12, but the manufacturer can be sure that it will always be above the 10-10-10 specification. This is often not done out of malice, but out of the fact that the fabrication process itself might create a significant amount of variance within the composition of the actual fertilizer being produced and the manufacturer always wants to be above the minimum. This means that if you want to get the true mineral composition of the product, you’ll need to send the actual fertilizer you want to copy to the lab. Never rely on the label when copying a fertilizer.

Flora Bloom by General Hydroponics
Label of a very popular hydroponic fertilizer. Trying to copy this fertilizer directly using this composition and “derived from” information, would lead to substantially higher costs, manufacturing problems and errors. This is common to a very large array of commercial hydroponic products.

Not everything that can be claimed is claimed. When a manufacturer decides to create a fertilizer product, it might decide to leave out a specific nutrient within the formulation that is there, but that they do not want to claim to prevent reverse engineering. This is often not illegal – you’re getting more than what you paid for from the point of view of the regulators – but it does mean that you’re going to be completely missing something if you just copy what the label says. This is a very common trick that is done with micronutrients, where a manufacturer will claim, for example, that the fertilizer has Fe and Mn, but will make no claims about Zn, B, Cu or Mo. A person copying the label would be missing these nutrients, so their plants would end up dying from deficiencies.

The “derived from” is usually not what it’s derived from. Usually a hydroponic product will contain a list of the inputs that were “in theory” used for its fabrication. This will be a list of commonly available raw fertilizers, but more often than not, fertilizer manufacturers might include a product from which the composition might be derived, that is significantly more expensive than the raw inputs that the fertilizer is actually derived from or add unnecessary inputs to the list. A simple example would be a fertilizer that is made with potassium sulfate, magnesium sulfate, and monopotassium phosphate. The manufacturer might choose to say it’s derived from potassium sulfate, monomagnesium phosphate, potassium carbonate and magnesium sulfate. You can probably derive the same final composition from both salt mixes, but the monomagnesium phosphate is a very expensive input compared to the monopotassium phosphate and the potassium carbonate is unnecessary in this product and will generate pH issues. This is a very common trick, designed to make reverse engineering attempts more expensive and to difficult manufacturing for people who try to copy using this information.

Inputs with non-fertilizer components. A fertilizer can often have nutrient ratios that appear to be impossible to get to given the “derived from” section they have given. This often happens when there are inputs within the fertilizer that contain non-fertilizer components that are not reflected within the label, or even within an analysis of the nutrient solution. For example a manufacturer might decide to create a calcium supplement containing calcium nitrate and magnesium nitrate and then the label might say it has way more Ca than what is possible from just the calcium nitrate. This means there is another source of Ca present but, what is it? In this case, the manufacturer might be using something like calcium chloride, which they completely neglect to mention within the label. However you should not make assumptions about what these things are, but actually perform an analysis to try to confirm your suspicions. Often assuming the “missing part” is something like calcium chloride can lead to you formulating something that is actually toxic to plants.

Additives that are not part of the mineral makeup. Many fertilizer formulations will also contain additives that do not have any mineral content and that therefore are completely avoided within the label. This is very problematic, since the effect of some hydroponic formulations might be largely related with some of this non-mineral content. The reason why a formulation might work significantly better than another of very similar nutrient composition might be the use of some additional substances within the formulation, such as undisclosed plant growth regulators, gibberellin inhibitors or other substances with very strong effects on plants. Even things as simple as non-ionic surfactants – which can significantly increase the wetting in media like rockwool – can make a big difference between two fertilizers with the same mineral composition. Knowing that these substances are there and copying them can be quite complicated and requires a lot of relatively expensive analysis to figure out.

As you can see, copying hydroponic nutrients is not just a matter of reproducing something that mimics what the label specifies (that would be very easy). It generally requires chemical analysis of the actual fertilizer to determine its mineral composition, judicious evaluation of the available raw inputs to evaluate which ones might be appropriate to reach the required composition and special consideration about the possibility of other additives that might be present within the product and the analysis to find out what these additives might be.



  • Toni
    September 20, 2020 @ 8:08 am

    Not sure what is the conclusion, do you recommend commercial fertilizers vs pure salts/chelates?
    I’m just a hobbyist but I find that commercial solutions are a rip-off and hardly add any value against pure salts and HydroBuddy.
    With great help from your blog I’ve managed to source most of the “pure” salts/chelates and I find it much cheaper (-90%) to blend my own solutions than to buy commercial ready made solutions.
    Plants like it as well so I don’t really see why would anyone throw money for diluted nutrients with a “brand” on it.

    It would be interesting to follow this up with a laboratory analysis of some of the most popular solutions and a recommended HydroBuddy formula for replication with some of the salts/chelates that are available from general retailers.

    • admin
      September 20, 2020 @ 2:32 pm

      Thanks for your comment! I absolutely advocate for using your own formulations if you can, properly formulating from scratch based on your own particular needs and circumstances is probably one of the best things you can do to reduce costs and increase your chances of success. This post is just meant to show you that truly “copying” a commercial nutrient you like is not as simple as it might seem at first, because the labels are not accurate and there are often things in there that the labels do not even mention. That doesn’t mean you cannot create your own formulations, just that if you want a true copy of a commercial nutrient, then you need a lot of additional information.

      About a post sharing formulations of popular fertilizers derived through lab analysis, that takes a lot of time and money, reason why I only do that work for people who specifically pay for it through consulting. Note that it’s not only the lab analysis you need, it’s also a lot of experience in knowing what salts to use -to know which ones are different from the ones on the label or not included there – and also including additives that are present and not disclosed.

      • Toni
        September 20, 2020 @ 11:41 pm

        Thanks, fully understand that there are great costs and efforts in such analysis that cannot be financed from this website only.
        I’m not a professional in the fertilizer industry but i do know how the business is developed. As such, i cannot imagine that any of the major brands use some special “ingredients” that are so exotic, expensive, and unavailable to the general population. What they do is to instead focus on marketing, packaging, and colouring their product so to create uniqueness and confusion while using massproduced salts and chelates.
        Of course, many of the generic salts might be only available in 25KG packages and as such it could be too much for one person to acquire.
        I know that there is the cost function in hydrobuddy but it would be a good to produce a table/matrix just to show the cost of 100 ppm of each of the main nutrients as comparison in using generic salts vs commercial solutions. I bet the table will show that using own salts formulations the cost will be <90% of the commercial solution.

        You have done a great job in educating us all about hydroponics and i hope that you can find the motivation to keep on producing such a great content for free :)

  • AgTonik LLC
    September 21, 2020 @ 8:40 am

    I have a 2:1 cal-mag that I want to reverse engineer. It uses calcium citrate, calcium glucoheptonate, calcium carbonate and calcium acetate, magnesium acetate, magnesium glucoheptonate, magnesium citrate and cytokinin-dominant kelp (Ascophyllum Nodosum).

    Can you recommend a business for analysis/testing that can assist me?

    • admin
      September 21, 2020 @ 8:52 am

      Thanks for commenting! The specific labs available will depend on where you live. For starters you would want to get a N/C/H/O/Ca/Mg elemental analysis of the mixture and of the inputs and then from that analysis reconstruct the potential mixtures that might generate that specific composition. I am also available for consulting if you would like my assistance in helping you reverse engineer the product, feel free to email me using the contact page.

    • Toni
      September 21, 2020 @ 9:13 am

      This sounds more like a nutrition supplement for humans than a plant fertilizer :)
      Are you sure that the application is “hydroponics” ?

      • admin
        September 21, 2020 @ 9:17 am

        Thanks for your comment! Many Ca/Mg supplements in hydroponics use inputs like these, because they want to add Ca/Mg without adding a lot of additional nitrogen. It can give significantly better results than using salts like calcium nitrate, depending on the circumstances.

      • AgTonik LLC
        September 21, 2020 @ 9:18 am

        @toni It is a flowering cal-mag supplement intended to transition when tissue sample calcium needs are highest. Extra nitrogen in traditional N cal-mag supplements is un-needed for the most part.

  • Keesje
    September 24, 2020 @ 2:13 am

    Dear Dr. Fernandez, besides the overpriced special hydro fertilizer brands (which are indeed overpriced) there are also several other brands used by commercial growers.
    Brands like Yara or Peters for example.
    With these brands you don’t have to mix anything and they have a wide range of products.
    There are also not very expensive. A 20 kg bag will last a long time for a small scale hobbyist.
    So they seem to me like a cheap alternative to the overpriced brands, and just as good (if not better) then ‘homemade’ fertilizers.
    What is your opinion about this?

    • admin
      September 24, 2020 @ 8:32 am

      Thanks for your comment! You should use whatever fertilizer you can get that achieves the best ratio of control/convenience/price/results for you. The way of doing things that gives people the best control and price is to use raw salts to mix the fertilizers themselves, but this control comes at the expense of more responsibility and less convenience. For this reason some people prefer to use commercially mixed fertilizers, some will prefer fertilizers that are sold as liquid concentrates because of the reproducibility in composition and formulation versus other solutions, while others will prefer solid mixes that are cheaper like the ones you mentioned. In the end you should use whatever fits your budget, abilities and goals best and this means different solutions for different situations.

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