Used tank help

[dinnerflexor]

I bought a used 20 gal. looks to have been resealed. Holds water. some of the sealant looks to have bubbles and some of the bubbles are black with either mildew or algae. What do I do to get it ready? How do I get the black/brown out? (I know how to cycle, just wondering about the cleaning and prepping part)

 

[cgthebeast]

I would tape it and stablize it, then scrape all the old sealient off and re do it.

 

[dinnerflexor]

What kind of caulk? I'm assuming waterproof silicone but do I want mildew resistant or not? Will that caulk say if it's safe for aquariums? Sounds like a major project:/

 

[cgthebeast]

No, you don`t mildew resistant, its not aquarium safe. you want to have one that says 100% silicone. It should say aquarium safe on the bottle. You would need to keep it dry and out of humidity the mildew or mold should not occur again.