thank you sensi for you response. so that brings me to another question. if what i have is algae buildup...is that bad? or have i read in some places that algae is not bad and that plants can still thrive in the presence of algae so i wouldn't get to excited about cutting roots. i do have h202 in my system and add a little bit every day. will that take care of my algae? along with blocking out all light? should i dry to rinse the roots with a light h202 solution to wiggle the algae off? any suggestions on how to take care of algae stuff would be helpful. thanks again sensi.