Join Date: Mar 2010
Location: Gatineau, QC, Canada
I used 8 bags in my 59g : 3 Eco Complete, 5 Fluorite Black (they are different weights but about the same volume). I have some hills and mounds in my aquascape though, it depends if you're going for a flat surface or more hills. I think you should aim for around 2" all around, at least.