I love my eco-complete type substrate, actually I could only get Floa Max here. It is really dirty and needs washing MANY times. I got to thinking that if I washed it until it was clear, I might be washing away half the nutrients I'm paying for. I washed it 4 times until the worst was out, then went ahead and put it in the tank. Then I did an old school trick of covering it with only enough clean aquarium gravel to seal it in. (About 3/4") This way my water got clear and only clouded a little when I poked the plants into the substrate. The flora max is light enough that gravel vacuuming would have been a challenge, and smooth gravel is friendlier to my corys. Roots are well into the flora max but gravel keeps the "silty" stuff at bay.