Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
When I mix these into a bottle to make a wet fertilizer I use 2 parts CSM+B: 1 part chelated iron. I think this is a common ratio, though I have also seen 1:1 ratios used.
How lacking in iron are your plants? CSM+B has some iron, so 2:1 might be just enough extra iron for an average set up, a substrate without iron added.