There's been algae on the tank walls for a while now. I can't scrub it off. I have the light on for seven hours each day. It's a planted tank. I've had algae on decor and plants too but that's been easier to wipe off. I have a snail and platies that sometimes pick at the algae. I don't want to get any more algae eating livestock. Should I give one of those algae remover bottles a try? Because it won't come off.