I just picked up a 100g tank second hand for a price I couldn't refuse. The tank is in great shape but after cleaning it up a bit I noticed a small clamshell shaped chip on the bottom glass of the tank on in the inside just above the seam. There is a small hairline crack going through it. Is it still safe for me to use it or can I fix it? Or am I going to have to scrap it? The glass thickness is about 3/8" and the chip is about 1/2" wide.