I found some old gravel stuffed in a cabinet, and I want to use it for the 5 gallon I'm setting up. I'm not sure what kind of fish I used it with, or what eventually happened to the fish, but how well do I need to clean it before using it?
This tank has been in storage for a while. I filled it up and sat in on a dry surface to check for leaks. While sitting there, there were no leaks. When I tipped it on it's short end, I noticed that in the middle, at the bottom (on the long side), water came out between the black rubber and the glass. Is there likely a leak somewhere?
Also, at the top of the tank on the glass, there an ugly white stain/residue all around the tank. Brushing with a toothbrush didn't do anything. What can I get rid of it with?