i just added a rock to my tank that was found in a lake. i cleaned it and everything. i actually got it like a year ago and it was in my old tank but took it out and it has been sitting in a bucket. so anyways i found it today and put it in my tank after rinsing it in very hot water. after being in the tank for a few min is started to leak tiny bubbles, and has been for a few min now. is this bad? or normal?