If EI uses KNO3, KH2PO4 and Micros. What is the need for all these other types of fertalizers? Can anyone give me some info on each and why they may be used?

Calcium Carbonate
Calcium Carbonate (Fine) 1 lb. CaCO3

Calcium Chloride
Calcium Chloride 1 lb. CaCl2


Calcium Nitrate
Calcium Nitrate 1 lb. CaNO3


Calcium Sulfate
Calcium Sulfate 1 lb CaSO4


Iron Chelate 10%


Magnesium Sulfate
Magnesium Sulfate 1 lb. MgSO4


Mono Potassium Phosphate
Mono Potassium Phosphate 1 lb. KH2PO4


Potassium Nitrate
Potassium Nitrate 1 lb. KNO3

Potassium Sulfate
Potassium Sulfate 1 lb. K2SO4

Re: Ca & Mg... Not all local waters are created equal, and many are low in Ca and/or Mg, which the plants need. Most micros do not have them, or perhaps not enough of them. I suppose also that in a non-CO2 tank with no water changes that your tank could use up the available Ca and Mg. There are probably other special reasons for CaCO3, CaCl2 and CaNO3 that I do not know.

Re: Iron chelate... Most micros have iron, but I guess some don't.

Re: Potassium sulfate (K2SO4)... If your fish load is fairly high, they create NO3 with their waste. Therefore, adding KNO3 may ramp up your NO3 too much. K2SO4 is a good way to get your K without adding more NO3 to your water. With EI, K2SO4 can be used as a substitute for KNO3, if your nitrates are already high enough.