Good morning Stoners. Green Goblin. Everytime I see a rig like this or just a bucket catching roof run off the first thing I look at is what kind of roof it is. In my roofing days, one of the selling points of even the cheapest shingles was/is the anti fungus (zinc chips) mixed in with the other tiny chips covering each shingle. With mycos and other beneficial fungi used more and more, I always wonder how much, if any, using the roof run off will effect their efficiency.