I throw in few copper fittings into my buckets, no algae, and a little copper is good in a chickens diet.I use this. I've never cleaned it in almost 8 months. In this pic, it looks discolored towards the bottom and as if algae may be growing in it, but I can assure there isn't any. There are about 5 or 6 pennies in it. Copper is a natural biocide and will not harm the chickens. (Think about all the copper pipes in your house.) I fill it with the hose from outside the run. View attachment 1251242