I have hard water stains all over my aquarium. I have it on my filter too. I tried some safe and easy which does absolutely nothing to take it off. Vinager seems to help take a good chunk of it off if it’s building up. But it doesn’t seem to help take all of it off. I heard using a steel wood pad might help. I’m scared that some of them might have some anti-bacterial chemical in it. Just like kitchen sponges do. Any type of scratchy sponge I can use that’s specially made for aquariums that might help? I know I’m not the only person that’s experienced stubborn water stains on an aquarium. Or can anyone give me the name of a brand of steel wool that’s safe for aquariums?