what fertelizers mix, or don't mix.

[Davejt]

I know it's here somewhere, but I cannot find it all in one place and my brain has gone to mush this afternoon comparing VOIP phone services So:

I am wanting to premix a daily fert mix (or 2 for odd even days) with as much as possible in it to simplify dosing.

• Which of these compounds will mix and store together dry?
• Which will mix and store together in a solution?
• which will not stay in solution?
• which have to be dosed at a different time then the others.

TIA

CSM-B Plantex
Iron Chelate
Ferrous Gluconate
Potassium Sulfate
Potassium Nitrate
Mono Potassium Phosphate

Dolomite
Calcium Chloride
Calcium Nitrate
Calcium Sulphate
Magnesium Sulfate

No I'm not using all of them right now, but want to put a post-it in my computer to cover all the permutations.

 

[Philosophos]

You can pretty much throw all of it together except the KH2PO4 with things that aren't K+ based. The CaSO4 isn't very soluble; bad for stock solutions. No clue about calcium nitrate.

In practice, I like to group my KNO3, KH2PO4 and K2SO4 together in one batch. They're all K+ bases, they place nice together.

The iron chelate, CSM+B and MgSO4 also get along well enough.

I don't dose calcium because the water here is hard; plenty of GH that isn't carbonates. For the times I use RO, I keep a solution of CaCl2 around in its own bottle.

 

[Biollante]

What Dan Said

Hi,

What Dan said.

Dolomite, C2CaMgO6 is hard and non-soluble in water enough that to use as substrate or to cap for a substrate.

Calcium nitrate, Ca(NO3)2, I have never used but I think as with Calcium Chloride that Dan mentions, I think I would keep it separate.

Biollante

 

[Davejt]

Thanks for the help, starting to make sense. Sounds like the Plants like a 3 course dinner K's, micros's + iron, and Calcium on the side.

 

[Biollante]

Yep.

Thanks for the help, starting to make sense. Sounds like the Plants like a 3 course dinner K's, micros's + iron, and Calcium on the side.

Hi,

Yeah that is about the deal!

Biollante

 

[Davejt]

Part two:

Can anyone help me complete this chart, or point me to one? Basically how many grams of each does what in ten gallons of water. How many grams of each that is soluble in 1liter would be useful as well.

0.3 grams of KNO3 will raise the nitrate level of 10 gallons of water 4.84 ppm
0.1 gram of KH2PO4 will raise the phosphate level of 10 gallons of water 1.84 ppm
1.0 gram of K2SO4 will raise the potassium level of 10 gallons of water 11.82 ppm

CSM-B Plantex
Iron Chelate
Ferrous Gluconate
Potassium Sulfate

Dolomite
Calcium Chloride
Calcium Nitrate
Calcium Sulphate
Magnesium Sulfate

Thanks.

 

[Philosophos]

Calculating for a desired concentration yourself isn't hard, and you know you'll have reliable results. With this formula, you won't need the chart.

Lets use KNO3 as an example. Simply take the atomic mass of KNO3 (add up the atomic mass of 1 potassium, 1 nitrogen and 3 oxygen from your periodic table or use wikipedia):
101.10332g/mol

Then divide it by the atomic mass of NO3:
=101.10332/62.00501

If you stop here, you'll get the quantity of KNO3 in mg that it takes to raise 1L of water by 1ppm.

Moving on to larger dosing, multiply by your desired ppm of NO3 (lets say 20):
=101.10332/62.00501*20

If you stop here, you'll get the quantity of KNO3 it takes to raise 1L of water by however much NO3 you want in it.

Finally to dose a column, multiply by the number of liters that you want to dose (10 gal is about 37.8541L, use google to convert or multiply by 3.78541):
=101.10332/62.00501*20*37.8541

This ends up working out to about 1234.47mg of KNO3 to get 20ppm of NO3 in 10 gal of water. For practical purposes, call it 1.23g

If you want to make the chart, it's not much of a change to do it the other way. Simply switch the places of the two atomic masses:
=62.00501/101.10332

Multiply by the weight you're adding in mg:
=62.00501/101.10332*1000

Divide by the number of liters you're adding it to:
=(62.00501/101.10332*1000)/37.8541

This ends up being about 16.2ppm.

 

[Davejt]

Thanks for the instructions Dan! Guess I'll knock the dust off the ol spreadsheet !