My routine for the water tank is as follows. Flush out all anti-freeze from the winter with fresh water. I then pour about a cup of bleach in the water tank and fill it to mix around, and run the mixture through all the lines, faucets, spigots etc. I will then usually let it sit for a couple of days, then flush it out. Once flushed out, I check the filter on the water pump, which is usually clean and clear. In general, I will typically add a couple of caps worth of bleach every time I fill up the water tank throughout the season. I also fill the tank using an RV inline filter and will run it down to empty periodically through the season. We don't use the water other then for washing things and the head. I have never experienced a foul water smell or problems doing this routine.