hey i was wondering if the reason my water turns green so fast is because its on a window and the sun hits it directly before i had algea with my black sand now with my white sand it looks like the water is turning green is this because of the sun?
well if the sun is hitting the back or sides of your tank you could put a black background / sideground on it to block the sun if it's hitting the front of your tank well your preety much left with moving it as your only option.
I would not just paint the back of the tank black and be done with it. Sure it will stop the light, but the sunlight will drastically heat the water up. Think of how hot asphalt gets even in the winter with sunlight hitting it.
I'd try some blackout curtains or if that doesn't work, put a layer of aluminum foil after the black background, it will reflect most of the sunlight away from the tank.
I dont think i should worry about the water getting hot i do have blinds and two backrounds and a heater my water temp is at 81 i dont think that will be a problem
I think im going to look into this stirilizer thanks for tht tip man.