PlantGuy's Calcium Sulphate CaS04 (1lb)

Which variation of CaSO4 do you sell? CaSO4·2H2O or CaSO4·1/2H2O? Thanks.

It's gypsum... 2h20

Is this suitable for hydroponics? Could it be used to add calcium?

yes it could..

I have been unable to find super sulfate anywhere in Canada. Im trying to build a hydroponic mixture using Potassium Sulfate, Potassium Nitrate, Magnesium Sulfate, and the Super Phosphate. Do you have anything that could replace the Super Sulfate? I would like to try to use your company to support a Canadian company.

This isn't really something that would have a place in a planted aquarium so I don't carry it .