I found a great deal on a used tank in my area and was wondering what I should watch for. Obviously, I should ask/check for leaks but is there anything else I should ask about? Is it important whether it was a fresh or salt tank? My biggest concern is if they used any chemicals in the tank, and if so can those chemicals leech into the glass and cause me problems. I know its a loaded question, but I want to act fast to make sure I get it before anyone else has a chance. I hope I asked this in the correct forum. Any and all responses are greatly appreciated.