I have my water perfect but I am getting small rust stains on the bottom by one of the vents. Any ideas on a quick easy way to just clean them. I'm thinking a small amount of some type of cleaner or is it better to add some new chemical like a scale remover. I am currently using brominating tablets and some shock. I'm happy with my water conditions but if adding another chemical is the answer I'm great with that. Thanks in advance. Rico