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Homemade Nutrient solution problem

Posted by Damjan none (My Page) on
Sat, Jun 8, 13 at 11:42


I'm trying to mix my own hydro solution since i cannot find any pre-made fertilizers in my country. Following a formulation with hydrobuddy i'm stuck with lees on the bottom of the tank.Through the process i used clean and accurate instruments, the nutrients i used are:

Liquid calcium nitrate (Ca 40%) Ca 9.7% N 6.8%

Potassium Monobasic Phosphate P52% K34%
with Fe 100ppm As 100ppm, Cd 0.025ppm, Mg 100ppm in EDTA Form.

Potassium Nitrate P46% N13%

Potassium Sulfate K50% S18%

Magnesium Sulfate (16%) Mg min.18% S13%

Solubor B17.5%

And for the other trace elements i used pack of:
Fe EDTA 6.9%, Mn EDTA 3.4%, Zn EDTA 1.62%, Cu EDTA 0.26% and Mo 0.1%

Almost all the elements are packed in cheap plastic bags. only the micro elements, solubor and the calcium nitrate are sealed good from light and air.

Follow-Up Postings:

RE: Homemade Nutrient solution problem


Here in American P & K values are listed as Oxides. N is listed as actual N. It is my understanding Europe Lists all Nutrients as Actual values no Oxides. In other words 10-10-10 in America would be listed as 10-4.4-8.3 in Europe. The Oxide of P is P2O5 and K is K3O.

You must be listing your Percentages in Oxide form, from the numbers I am reading.

I guessing ""LEES"" on the bottom of the tank is another way of saying "Precipitant" on the Bottom of the Tank?????

When mixing Fertilizer compounds you don't get all pure water soluble elements. therefore the trash in these compounds Precipitates out of the compound and fall to the bottom of the tank because they are not water soluble.

When Talking about soluble fertilizer we measure the solubility as either COLD water or HOT water soluble. You might try premixing with Hot water. I find Calcium Nitrate particularly hard to dissolve in Cold water and use a hot water premix that I let cool before adding to my tank.

As far as Buying Hydroponic fertilizer, IMHO it is a rip off because it is only a soluble form of fertilizer. Plus Fertilizer elements are a Commodity, NOT A BRAND. I refuse to pay the high price of Hydro store Fertilizer.

I hope this helps, Good Luck


RE: Homemade Nutrient solution problem

Thanks for your reply, I'm sorry for my English.

The salts are listed as 100% water soluble, but their not all sealed good from air and light. I can see huge granules in the potassium phosphate, and also small ones in the mg sulfate and potassium sulfate. can this affect the plant uptake or its just problem weighting ?

the output of the calculator is:

Target ppm------------Result ppm

N(NO3-) 100---------73.4
P 40---------------------27
K 200-------------------209
Mg 20-------------------36.7
Ca 100-----------------118
S 53--------------------29.8
Fe 3---------------------2.8
Zn 0.1-------------------0.63
B 0.3--------------------0.3
Mn 0.8------------------1.34
Cu 0.07-----------------0.10
Mo 0.03-----------------0.03

RE: Homemade Nutrient solution problem


Most of your elements are with in range except Zinc which is high. Plants will up take available nutrients and grow well even if those nutrients aren't perfect. However I would watch Zinc because too much can be toxic to your plants.

Potassium Phosphate, Mg Sulfate and Potassium Sulfate you might try dissolving in HOT water and then letting it cool before adding it to your reservoir.

English is a second language to me and I live in the USA since I was child. My English grammar is not great.


RE: Homemade Nutrient solution problem

Thank you very much, i will post again in few days :)

RE: Homemade Nutrient solution problem

While the salts may be 100% soluble, the fertilizer is not 100% "salts". It may be that other percentage of material in your fertilzers are what is precipitating out. That is what Ricone was trying to say.

RE: Homemade Nutrient solution problem

I still get precipitation, for the solution i'm using tap water with the following info:

N 7.05
K 0.99
Ca 104.25
Mg 22.75
S 13.17
Fe 0.013
Mn 0.004
Zn 0.004
Cu 0.001
Na 7.92
HCO3 389.00
Cl 8.32
Cr 0.003
Ni 0.005
Co 0.005

The parametars are:
EC 0.79 ds/m
pH 7.28
TDS 572 ppm
SAR 0.18
Total Hardness 355

RE: Homemade Nutrient solution problem

If you can, take your calcium out all together. your water already has 104 ppm, so you don't need any additional. It may be that with the already present Ca, you're inundating your solution and causing it to bind with potassium.
Try adding your potassium component first(before the Ca component) and give it a day to see if it precipitates. Then try adding the calcium and see what happens after 24 hours.

RE: Homemade Nutrient solution problem

can the sulfates and potassium reacts with the calcium oxide in the tap water and cause precipitation? if so, i might try making 2 part concentrated 1:100 solution with rain water and then mix in the nutrient reservoir and see what happens

RE: Homemade Nutrient solution problem

i meant calcium carbonate.

RE: Homemade Nutrient solution problem

The rain water did't work out, i guess there was some bacteria in the solution. i used destilated water to make the 3 part concentration and aerated tap water in the reservoir. Found that high ph made the white precipitation, i add 1.5ml 9% white vinegar per 1L water to bring down ph from 8.2 to 5-6 which quickly goes back around 8 every 4 hours or so. I read that positive ions bring down the ph and can be used to buffer solution around ph of 5.5 so I'll try adding N (NH4+) ammonia 10-20% of my total nitrogen and try sulfuric acid instead of vinegar and see if it works out.

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