Keeping Water in My Freshwater Tank During Storage?

There are some other factors that enter into the question. For those in climates with freezing temperature, the fresh tank has to be drained completely to avoid cracks.

Those that have access to treated city or water district normally have chlorine added that will kill any bacteria.

Our fresh water tank is not bolted down - rests in a frame under the dinette seat. So, I loosen the drain valve and when the water stops running, I lift the opposite end of the tank to drain every last drop from the tank.