I have a 7 year old gas hot water tank with a grundfos recirculating pump. The tank caught my attention because there was a puddle of water underneath the tank, and when I took off the cover at the bottom and removed insulation, the bottom of the tank was wet. I noticed a slow leak directly above the tank where fresh water comes in; it was dripping down onto the water tank and that area is rusted, including the hole where the hot water comes up out of the tank. The leak area had a lot of white buildup on the fittings. I fixed the leak and am waiting for the tank to dry out (which would tell me there are no other leaks, I think). We have hard water (don't know how hard, but ordered a testing kit). I would like to drain the tank, which has never been done on this tank. There is no valve between the recirc pump and tank. Should the recirculating pump be turned off, and how should I do that? And of course, how should I assess any damage done by the leak to the entire tank, the leak must have been there for months, if not years to cause corrosion on the outside. Any help would be appreciated, thanks!