I have been battling algae of different colours, in my three tanks. I have been removing decor and soaking in hot water. The decorations then just sit in my laundry room, for several weeks. This room is almost totally void of light. When I go to return them to my tank, almost all of the algae is gone. The odd time, I still need to brush it off the leaves etc. So, has anyone ever tried blacking out the aquarium to kill the algae on the gravel and sand? Any idea how much stress this would cause my fish? I do try to keep the blinds closed when it is btight outside, but I still get algae.