[WaterKeeper]

Sorry gang but I've been away for medical reasons and haven't checked things out for awhile. Fun, bleach works best on organic residues like dead algae or sponge material. I use about a cup to a gallon of water for cleaning. I just let it soak for a couple of hours until the object looks clean. I rinse it well and, as you said, let it completely air dry. That removes any remain traces of bleach. You can also add some thiosulfate or other dechorinating agent into the final rinse if you want to be extra sure. It is probably wise to take that step if the item is very porous, like rock or dead corals.

Vinegar is good to use for calcium deposits that bleach won't remove. Using it full strength is best but you can dilute it 3 to one for mild deposits. Once again soak the item and rinse it well after that. You really don't need to let it dry as a little vinegar won't harm the tank.

Even better for removing calcium deposits is citric acid. I mix a half cup of citric with a gallon of warm water and use that to soak the soiled item. Like vinegar, the citric only needs a little rinsing and any residue is harmless to the tank. It sounds like you have some iron deposits perhaps and citric is much better at removing them than vinegar. It is harder to find these days but if you look around you can find Mrs. Wages Citric Acid in the canning section of some stores for about $3 for a quarter pound.