Under the cubes we put the cocoa mats. It really helps the roots. Keeps the light off of them and keeps them moist. The roots grow all up into the mat.
The hugo blocks get moldy and grow algae. We put block covers on them to keep the light off of the mold and algae. It still appears but not as much. We have a lot of "Fannage" going on, so I tape them down. Otherwise they blow off. We got about 5 lbs off of these 4 lights.