If one does not want to bother with filters the simplest method is to fill the tank with Mexican water. Use it for showers and dish washing. Use garafons for drinking and cooking water. We keep a gollon jug in the fridge and refill as required When in area with known bad water we do not use it for any purpose. We have been sick many times from food. Never from water. No big deal to sanitize the tank when you return NOB. Reed; @ 2.5 gallons a day you must not have been showering in your unit. I would be worried about getting a skin disease from some of the CG showers. In some CG's they are NEVER cleaned.
Moisheh