We have 2 water tanks under the floor in the salon. Total, we have between 60-80 gallons of space. The tanks look pretty clean on the inside when we peeked with the flash light. A good bleaching won’t hurt though. For now, we will use the tanks to flush the potty and as rinse water. We are debating if it would be safe enough to run the tank water through a Brita filter for drinking purposes. We are concerned about chemicals as we have bug bombed several times.