I'm using rock wool as a seed starter. It has become clear that I need to protect the rock wool from the light in order avoid algae buildup. I was wondering what methods are used to do this. Can you implat the rockwool into coco coir. I have tried burying it with hydration, but if the lights are strong enough, the alge still grows on the rock wool. I'm using a 1000 watt metal halide in a cool tube at 2 and a 1/2 feet.