Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
There are a few fish (Cardinal Tetras for example) that cannot handle extra calcium, so I would find out if you need it at all. Plants and fish do take some calcium out of the water, it is a necessary mineral, and so is magnesium.
Can you get a water report from the company that supplies your tap water? Or will you be using RO for this tank?