[rames14]

The fresh water tank is build so the drain is at the lowest point. I do not put any in the tank and have never had any problems. Make sure to drain the tank and the low point drains. I run a little into the water heater and also I dump a little into each drain - more because of the fact there you have traps that will hold water by design. Again, the tanks are tapered toward the dump and built to "not" hold liquid. Just my thoughts.