Peroxide fresh water

I'd suggest using peroxide just to be safe. If you use 1 oz per 10 gallons of water you don't have to drain it. you won't taste it and unlike bleach you do NOT taste it, it won't do you any physical harm (even if you use a stronger dose than 1:10) and it won't hurt your rubber or plastic seals. Also, put a sprayer on the brown 1 qt bottle of peroxide and use it to spray showers, kitchen sinks, sewer lines etc. Just remember--peroxide deteriorates faster than bleach so you need to 'redo' more often, but since it is so cheap--no problem. Keep it in a colored bottle like the original brown as sun light will destroy its POWER.