I have determined the water I have been pumping out of the bilge is coming from the fresh water tank. The plumbing that leads to and from the tank is located on the top and not suspect. As near as I can tell the tank must have a hole in the bottom somewhere. I would guess some type of abrasion. Without knowing for sure I ask this question. Can the poly tanks be repaired? Or, will it need a replacement? It looks to be a few hour job to remove and replace the tank and I want to be prepared to handle it before starting.