I recently bought a used fish tank which had mold in the sealant on the sides of the tank. I scraped the old stuff and resealed it. It was my first time using the stuff. I applied it really thick on the left to corners (remember, it was my first time ), and thinner on the other side. There are a few tiny bubbles in the sealant, pin size. Does this sound ok. I'll find out sooner or later if it worked. What are your opinions on sealing it yourself???