My freshwater fish tank (I only have one goldfish, but he's a pretty big one and I've had him for years) sprung a leak the other day, and I've been meaning to fix it up. Although my aquarium is pretty old, I figured sealing the leak would be worth trying before going out and buying a brand new tank. However, the aquarium sealant at Jack's Aquarium and Pets was pretty expensive, so I was wondering if plain old silicone from a hardware store would work. The research I've done online seems conflicting; while some people say that any silicone is fine, I've also heard that plain silicone has anti-mold/mildew agents that can harm fish. Would FDA-approved hardware store silicone be any different?
Also, a worker at the pet store told me that, in order to fix my leak, I'll have to scrape off the original sealants already on the tank and re-apply my new sealant - Apparently, new sealant will wear off if I just place it over the leak. Is this true?
Thanks for the help.