Planted Tank Obsessed
Join Date: Jan 2007
Location: ABQ, New Mexico
I have S-grade in my 135 and it grows plants fine. At first I only used root tabs but now I have pressurized CO2 and dose my ferts through the water column. So to answer your question, I do not think you will need to add anything unless you really want to.
The only issue I have had is keeping plants rooted when they are first starting off, so you may have to replant some that are floating, but they will establish after awhile. I love the substrate and so do my Cichlids who dig in it all day. That may be why I can't keep my plants rooted!