So they do leak if they are not turned on, the filter i mean? I dunno, my mom said it could be leaking cause the filter is not turned on.. im not sure if she knows what she is talking about or not lol. So i thought i would see if anyone else had this problem .. Cause i filled my tank with the salt and water and sand and live rock and yada yada, then i let it sit, next thing i know i have water coming from either the back of the tank somewhere or the bottem seam..