Tuesday, July 6, 2010

Preparing Your Own Hydroponic Nutrients : A Complete Guide for Beginners

Chances are that if you are into hydroponic gardening and you live in Europe or in the US you have been buying your nutrient solutions from one of the many hydroponic nutrient sellers available locally. Generally people do not prepare their own nutrients because they consider this task "terribly difficult" and they prefer to keep buying previously made formulations so that they don't have to deal with the technical problem of making their own fertilizers. What most people don't realize is that the profit margin of hydroponic nutrient producing companies is HUGE. You would be surprised to know that each one of those concentrated nutrient gallons you buy costs only a few dollars to make (sometimes even only pennies) and you are probably paying a few times what the whole fertilizer is worth.

Obviously if you are going to be growing plants for a long time or if you simply want to grow a large garden the buying of this commercial nutrient solutions is not an option and starting to make your own formulations - adjusted to your own needs - becomes the main priority. On today's article I will be speaking to you about how to prepare your OWN solutions using my nutrient solution calculator, carefully explaining to you what you need, where to buy it and what you should expect. I will guide you through making your own first A+B solution by YOURSELF getting all the chemicals and utensils you need easily and economically.

So what do you need to make your own nutrients ? The list below shows you the things you will need to start making your own A+B solutions. You will notice that you will need two scales since we are going to have to weight two "nutrient sets" with different precision, micro nutrients (which are used only in small amounts, need to be weight more precisely) and macro nutrients (which are used in larger amounts and therefore need scales with larger capacity).
  • Scale that can weight down to 0.01 g at a +/- 0.01g precision (something like this is perfect, just search 0.01 g scale on ebay to view similar products)
  • Scale that can weight up to 1kg at a +/- 0.1g precision (something like this)
  • Two Empty one gallon containers with caps
  • Plastic Spoon
  • Plastic small container (to weight salts)
  • A source of RO or distilled water (your tap water will NOT work)
  • Download my hydroponic nutrient calculator here.
  • Download the formulation you will be using here.
Now these are the chemicals you will need (an online purchase link is included for each one) :
  • Yara Brand Calcium Nitrate (here)
  • Magnesium Sulphate Heptahydrate (here)
  • Potassium Nitrate (here)
  • Copper Sulfate Pentahydrate (here)
  • Potassium Monobasic Phosphate (also known as mono potassium phosphate) (here)
  • Manganese Sulfate Monohydrate (here)
  • Zinc Sulfate Dihydrate (here)
  • Sodium Molybdate (dihydrate) (here)
  • Boric Acid (here)
  • Iron EDTA (NaFeEDTA) (here)
These chemicals can be bought in a variety of places but there is a link next to each one showing you a link where you can actually make the purchase. Often it is also possible to get these chemicals on ebay. The purity may not be as guaranteed as when purchased from a regular supplier but it is good enough for practical purposes in hydroponics. This is an example of Sodium Molybdate of a decent quality being sold there.

Of course you may see right now that the initial investment might be significant (from 100 to even more than 500 USD depending on whether you buy 50lb or 1lb quantities of macro nutrients) however after this purchase you will be able to produce more than one hundred gallons of concentrated A+B solutions which would cost you more than 10 times the price you will be paying if you bought them commercially. After doing the math you will see that this is a GREAT way to save money and produce your own solutions ! Hey you could even start selling to the neighbors ! :o)

After you buy the chemicals simply open my hydroponic calculator and load the general_beginner.txt nutrient formulation file you downloaded earlier on the calculator (use the "add external" button on the "Desired Formulation" tab. Then click the A+B solution button and select the "calculate weights for specific stock solution volume" option and input 1 (choose gallon) on the edit box above it. Now go to the "nutrient salts used" tab and select the salts mentioned above (make sure you select Yara Calcium nitrate instead of the regular one) .It is now time to go back to the "desired nutrient formulation" tab and press the "calculate formula !" button. Your screen should look like the picture shown below.
Now that you have calculated the weights needed you should go to the "calculation results" tab where you will be able to find the weights of the different nutrients you need to prepare the solution. The results of the calculation are showed below. You should now follow these steps to prepare the solutions :
If the chemical weights more than 10g weight it on the "less accurate" 0.1g scale. If it weights less on the "higher precision" 0.01g model.
  • Fill each one gallon container with half a gallon of RO or distilled water
  • Weight one salt on the container you set apart for measuring. Make sure you always DOUBLE check the weights and the appropriate A or B gallon container you need to add the salt to.
  • After you measure the salt transfer it to either the A or B gallon container (depending on which one it should go into). Use a little bit of water (RO or distilled) to transfer any remains that cannot be easily added and dry the container you are using to weight before measuring the next salt
  • Shake the container where you added the salt and make sure it is fully dissolved before measuring and adding the next one.
  • Do the same as above for all the salts
  • After you are done adding the salts add half a gallon of water (again RO or distilled) to each container
  • Then seal the containers and shake them vigorously
  • You have just prepared your first batch of self-made nutrient solution ! (Yey !!)
The above formulation is a general multi-purpose blend that should allow you to grow a large variety of plants. You simply need to add 10mL of A and 10mL of B for each final LITER of nutrient solution. You should use your pH meter and EC meter to adjust these values as you do with your regular commercial nutrients.

It is very important now to keep your chemicals stored in air-tight container in a dark and cool place. Some chemicals like calcium nitrate will absorb moisture and become useless if you leave them in contact with air for prolonged periods of time !!!

Of course, once you are more comfortable with preparing your own nutrients you can go to the A+B+C tutorial or research the available literature for some custom formulations available to grow each one of your plants under its favorite nutrient levels. I hope this tutorial has allowed you to reach a new level in your hydroponic gardening experience, hopefully accompanied by a drastic reduction in your soil-less gardening costs !

Note : Please leave a comment with your experience with the tutorial and with any links, phone numbers or addresses of your local chemical suppliers (if you have already located some you like). I will add them to a future feature of the calculator which will hold a chemical supplier global directory :o).


  1. Hi Daniel,

    Your recent articles with so many examples is really helping in understanding about nutrients and also to make your own nutrients which will help in experimenting. Good effort and really appreciate your contribution.

    0.1 precise weigh scale link is taking to 0.01 weigh scale. Please correct it.


  2. Hi Raurs,

    Thank you very much for your comment :o) I am glad my tutorials are helping you understand how to prepare your own nutrients and how to experiment with the calculator.

    I hope you continue to enjoy the tutorials and my website. Thanks again for your comment !

    Best regards,


    PS : I have just fixed the link :o) thank you for pointing that out.

  3. Hey Daniel,
    I was wondering if U could add some more salts to the program. Here is a great site to help (http://www.hydro-gardens.com/fertcomp.htm).
    I was hoping you could add some of these if not all-
    Calcium Chloride
    Mono-Potassium Phosphate
    Potassium Chloride
    Di-Ammonium Phosphate
    Potassium Hydroxide
    Also by using these (chalets)
    Calcium Chelate
    Copper Chelate
    Iron Chelate
    Manganese Chelate
    Zinc Chelate
    wouldn't these change the possibility of precipitation?

  4. Hello N,

    Thank you for your comment :o) I will be adding more salts to the program before version 1.0 comes out however you should take into account that Mono Potassium Phosphate and Di-Ammonium Phosphate are already in the calculator (they are also called monobasic potassium phosphate and dibasic ammonium phosphate) make sure you check the formula in the future so that you know if a chemical is already added with a different name.

    Regarding the chelates, you have to be more specific as each MANY chelates are possible. For example iron EDTA (an iron chelate) is already added but other such as EDHA, DPTA, etc are also possible. Once you specify the EXACT chelates you would want me to add I will be glad to help :o) However I will be adding all the EDTA chelates of the metals you mentioned in the future version.

    Regarding the possibility of precipitation, it depends on what you want to keep from precipitating. Also remember that chelating nutrients that are widely used like calcium can have very detrimental effects.

    The chlorides and potassium hydroxide are already on my list as well as nitric and phosphoric acid.

    I hope you are enjoying the calculator :o) Thank you very much again for your comment,

    Best Regards,


  5. Hydroponics

    Nice post……such an useful information regarding hydroponics……Gud job dude!!!!!!!!!

  6. My Antivirus will not allow your calculator to run, flagges it as suspiscious ativity and removes it....Ideas jdkcubed@gmail.com

  7. Hello Joe,

    Some anti virus software may flag the program as suspicious because it downloads a text file with the latest version to compare it with its internal data and check if there are any new updates. However the program is totally harmless so you can tell your anti virus software to ignore it to avoid any such problems. Thank you very much for your interest :o)

    Best Regards,


  8. what do the "Purity %" field means? I'm using EDDHA Iron Chelate, its 6.0%
    How would I use this with the calculator? (I assume to choose Iron EDTA and double ther results, since EDTA is 12%, or double the potency) ?

    also, I'm getting a bit of a discrepancy with your calculator, here is my data:
    N (no3) = 217
    P = 60
    K = 180

    nutrient salts used:
    Potassium Nitrate
    Potassium monobasic Phosphate
    Calcium Nitrate

    your calculation results show
    Weights Of salts to Dissolve Directly
    KH2PO4 = 99.57g
    KNO3 = 102.31 g
    CA(NO3)2 = 572.19
    this gives a ratio of 1-1.02-5.74 of fertilizers used, respectively

    however, my hand calculation yields results
    of ratio 1-1.18-4.56
    using standard
    Potassium Nitrate 13-0-44
    Monopotassium Phosphate 0-52-34
    Calcium Nitrate 15.5-0-0

    so there seems to be some variation of the results, any reason why? I am willing to answer more questions if needed. btw, I am using
    profile for my ppm conversions. thx~

  9. Hello Christian,

    Thank you very much for your comment :o) Purity is related to the actual content of the pure salt within the solid you are using. Generally commercial salts will contain some material which is not the intended product and such difference should be taken into account to achieve maximum accuracy.

    In your case you should NOT use iron EDTA but you should add a custom salt with the adequate iron percentage of the iron EDDHA chelate. This is done using the buttons to the right of the salt list.

    Regarding the calculations the results shown by the calculator are correct. The ratio you are aiming for with 217 N, 60 P and 180 K would translate to an NPK of 1-0.63-0.92 since K is expressed as K2O and P as P2O5 in a traditional NPK representation.

    I think that you are a little bit confused regarding how nutrient concentrations are calculated and how you need to calculate nutrient percentages. However I can assure you that the results given by the calculator are correct and that the ppm values you input are achieved when the mass of salts specified is dissolved in the amount of volume you have input.

    Also bear in mind that calcium nitrate tetrahydrate has an N percentage of 11.9% and NOT 15.5%, this higher N percentage is attributed to what is commonly referred to as greenhouse grade calcium nitrate which is NOT calcium nitrate but a calcium nitrate/ammonium double salt. A salt with this composition is available as "Yara calcium nitrate" within the list.

    Thank you very much for your interest :o)

    Best Regards,


  10. Hi Daniel. Good calculator. I took some time to double check my knowledge, and yes I was confused about calculations and some misconceptions. Thanks for your time on making this blog and responding to my questions. A quick question if I may ask?

    You mentioned Calcium Nitrate tetrahydrate as being 11.9-0-0, but wikipedia shows it (i tried to research lol) 12.8-0-0


    Formulations lacking ammonia are also known: Ca(NO3)2.4H2O (12.8-0-0 + 18.3%Ca).
    This would give a 12.8%, is this a type or something different that is at play here with the 11.9 figure?


  11. Hello Christian,

    Thank you for your comment :o) I am glad that you have checked your knowledge and that you now agree with the calculator.

    Regarding calcium nitrate tetrahydrate,

    The molar mass is 236.15 g/mol. Since each mole of the tetrahydrate contains 2 moles of nitrogen then the percentage of nitrogen is (2*14/236.15)*100 which is 11.9% so the value in wikipedia is wrong. The percentage of calcium is (40/236.15)*100 which is 17%, not 18.3.

    I advice you always do these simple calculations yourself since wikipedia is wrong a good percentage of the time due to the fact that more often than not no one takes the time to check the accuracy of these contributions. I have just made the correction in the wikipedia page so that no more people face this error.

    Thank you very much again for your comment :o)

    Best Regards,


  12. OK, great program, I have already recommended to several people on another website to use, seems to be the simplest one available and very easy.

    Another question/comment. I was trying to match you Iron EDTA salt, using a custom field. I found that if I created a new salt, with Fe content as 1.3, it would match up almost exactly with the built in Iron EDTA. However, I have read that Iron EDTA is 13% purity of Iron, so the value should be 13?

    So, possibly the current Iron EDTA field built in has a decimal point discrepancy, giving a 1.3% purity instead of 13% ?

    Just checking, keep up the good work on the calculator, really useful app !


  13. Hello Christian,

    Thank you very much again for your comment and recommendation :o).

    Regarding your FeEDTA question, I have just checked and adding a custom 13% Fe salt gives almost the same results as the included FeEDTA. What happens is that you may not be taking into account the fact that the results displayed for the built in FeEDTA are for the preparation of a 1L, 1:10 concentrated solution as detailed on the label above the box. Therefore you should NOT dissolve it directly but prepare the 1L concentrated Fe solution and use 100mL per batch. However when you add a custom Fe salt you get the value to add directly and NOT to prepare a concentrated solution.

    Please read the examples and instructions on how to prepare solutions using the "dissolve directly" option, please remember that for this procedure a concentrated micro nutrient (1:100) and a concentrated Fe solution (1:10) MUST be prepared and NO direct additions for these salts must happen. Please pay close attention to the labels above the boxes where the values are displayed.

    In summary there is NO decimal point discrepancy and the included FeEDTA gives accurate results. If you want to add all salts directly instead of preparing concentrated Fe and micro nutrient solutions you need to have a reservoir volume of more than 4 cubic meters.

    I hope this answers your question :o) Thanks again for your interest and comments,

    Best Regards,


  14. Hi again Daniel. I have been using your program for several days now, and I think I am getting the hang of it. Its fairly simple and easy to use.

    1 question though, if I wanted to keep a dry/powder nutrient, could I simply mix the powdered components together in the appropriate ratios and amounts as given by the calculator, or would this cause a problem to mix the dry noots together? thx!

  15. Hi Christian,

    Thanks a lot for your comment :o) I am glad that after some practice you find the program easier to use ! I hope that other people you have shared this link with are also finding it useful.

    Regarding the storage of dry nutrients I would have to say that as long as you store the nutrients in airtight containers you should be okay but you should make sure they are well mixed every time before you weight them for use. If the containers where you store them are not airtight they will absorb a lot of water and become a useless paste.

    However don't worry if they become red or if some light brown granules start to form after storage. The salts will react with time when mixed together to form other salts such as dark transition metal phosphates, red iron nitrate hydrates, etc. However they will dissolve and they will work just as well with the initial ratios you prepared.

    Nonetheless if you can it would be best to prepare concentrated A and B solutions instead of dry nutrient mixes for longer term storage.

    I hope this helps ! Thanks again for your comment :o)

    Best Regards,


  16. Hey D,
    Was just looking at Cropking & Hydrogardens and I can't find Magnesium Nitrate. Do u know of any place I can find it.

  17. Hello N,

    Thank you for your comment :o) Magnesium nitrate is indeed very hard to find and often quite expensive. I think that you will need to look into providers such as Spectrum Chemicals to get it. I hope you are enjoying the calculator !

    Best Regards,


  18. Hi again Daniel

    Your blog has sparked many questions! I have a few questions about a statement above

    "If the containers where you store them are not airtight they will absorb a lot of water and become a useless paste."

    I had some calcium nitrate that was not stored completely secure or air tight. When I opened the package, I noticed at the top of the container, the granules and "fused" to create rather large chunks of calcium nitrate. I assume the calcium nitrate at the top of the container absorbed some water from the atmosphere air. So how exactly does this change the Calcium Nitrate? I assume is has absorbed a lot of water, does this change the chemical structure of it, or does it still dissolve in a water solution the same?

    Next, regarding the idea of mixing all the nutrients together and they will form a paste from the water absorbed from the air, does this paste change the chemical formula (ie: interactions of the salts mixed) or does it simply add a bunch of water weight making it impossible to weigh/measure? Just curious how exactly the paste will be useless, if dissolved in water will it be different, or will it simply be impossible to measure doses since the weight is distorted with so much water intake?

    thanks! Really great info Daniel here, I am excited to get rolling here with nutrients!


  19. Hello Christian,

    Thanks a lot for your comment and interest :o) I will now answer your questions :

    1. Calcium nitrate absorbs a lot of water if left in contact with the atmosphere something which may at first lead to caking (which is what you experienced).The problem is that the amount of water absorbed is not known and therefore you can never know how much calcium nitrate you are adding.

    2. In the case of premixed nutrients things become a little worse, it is not only the loss in accuracy due to the absorption of water but the fact that the water allows some reactions to take place, mainly the reactions of calcium, phosphate and sulfate ions, precipitating calcium sulfate and possibly some phosphates. So not only would you not be able to accurately add your nutrients (since they have absorbed a lot of unknown water weight (they can absorb as much as 0.5-5x the salts' weight depending on the conditions)) but their actual solubility properties will be affected and possibly a lot of precipitate will remain after addition.

    The problem is that some of the salts that are formed are very stable and their dissolution is kinetically very unfavorable (which means that they will in the end dissolve but it may take them days/months to get there). In the end, if you cannot store the premixed nutrients in absolutely air-tight containers this is not something you should be doing. It would be better if you just weight the salts for your reservoir when you do each preparation.

    I hope this answers your questions :o)

    Best Regards,


  20. wow! the master speaks!

    amazing as always Daniel

  21. Hi Daniel,

    Is it possible to use nitric acid in place of NO3?


  22. Hello T.J,

    Thank you for your comment :o) However I don't seem to understand your question. Nitric acid has HNO3 as its formula, when you add this to your hydroponic solution it reacts with water and dissociates into H3O+ and NO3- ions (nitrate ions), so if you add nitric acid you are adding nitrate. If you wanted to add all the nitrate in your hydroponics system as nitric acid you would then need to neutralize it with a basic source such as potassium hydroxide (KOH) which in the end is equivalent to adding a regular nitrate (like potassium nitrate) to your reservoir from the beginning. I hope this solves your doubts,

    Best Regards,