Thanks for the tip on clear tubing. I thought I had a brainstorm but looks like a brain fart. Never thought of algae problem with so little tubing. I did use the yeast and sugar solution and never had a problem. I'll try the vinegar thing now too and see what happens. I didn't have stunted growth problems with my first two crops and the rest was just a mess. The plants I did have when the rot problem started stopped growing after they were about 18". That was just a mess. I also discovered that I couldn't grow six plants in the system because it became too crowded. I'll get back with more info after I see how my next four plants do. So far, they are looking good, but are still very small to predict anything. I don't even know if they are male or female yet. I'll keep you posted. Thanks for your help and ideas. Willow