using epson salts in tank

Dissolve in hot water first if ur paranoid of it not breaking down

 

I always used as a foliar feed. Its simple and little chance of trouble with high salt concentrations. Just my 2 centavos

 

Dissolve a tea spoon in a cup of hot water and then add to a liter of cold water. Water in to the soil as you would normally do.

But most bottled nutrients will already have plenty of Mg in it already