We just returned from our 11,000+ mile round trip to Alaska. We experienced varying levels of water quality at the many RV parks where we stayed. We returned with a fouled fresh water tank. I have super-clorinated it twice and flushed it afterwards, but we still get discolored water when using the tank. Water is clear when we use city water, so the piping is not the problem. There is no way to scour the inside of the tank. I am looking for suggestions for cleaning the residue from inside the tank.

Put in bleach, make sure the tank is full and let it sit this way for at least 24 HOURS before rinsing.WoodGlue

I did this twice already for 2 days each with about 3 times the normal bleach concentration. No change to color of water after draining and filling tank with city water then using tank again.

Sanitize the complete water system by putting 1/4 cup of bleach for every 10 gallons of water. Run the solution through the system and let it sit over night.Flush system with fresh water. To complete run a solution of baking soda and water through the system to kill the bleach taste.

Are you running the pump to get the bleach water out or just using the low point drain. After letting it sit I would try opening the low point drain while running more fresh water through the fill port.

After you bleach the tank I would suggest draining it of as much water as possible and letting the tank dry out. I would add beach to your tank as a last step to draining it. You may have "stuff" growing on the roof of your tank. Also you may have dead bacteria stuck to the walls of your tank. Another more radical step would be to drill precision holes in your pure water tank. With one or two holes drilled, high in the tank, you could get a high pressure water washer and clean your tank. You would likely need special, home made fitting to reach most of the tank. If the hole is large enough you could get a garden hose as well as your arm in the tank. The holes that you drill could be glued shut. A better method, one that I have used in my black tank, is to purchase "test plugs" for the holes that you have drilled. Test plugs are rubber plugs that expand when you tighten a fitting on the outside of the test plug. All the big box hardware stores and most regular hardware stores have these items. This step is the most radical but it is the only method that I can conceive of to aggressively clean the inside walls of your water tank. I put a 4" test plug in my black tank. Long story about why I did it. I have used the test plug annually to clean my black tank thoroughly. I would do it again in a minute.

Cleaning fresh water tank | Good Sam Community

HappyKayakers
Explorer III
Aug 06, 2013
Are you running the pump to get the bleach water out or just using the low point drain. After letting it sit I would try opening the low point drain while running more fresh water through the fill port.
enblethen
Nomad
Aug 06, 2013
Sanitize the complete water system by putting 1/4 cup of bleach for every 10 gallons of water. Run the solution through the system and let it sit over night.
Flush system with fresh water.
To complete run a solution of baking soda and water through the system to kill the bleach taste.
yudamann
Explorer
Aug 06, 2013
I did this twice already for 2 days each with about 3 times the normal bleach concentration. No change to color of water after draining and filling tank with city water then using tank again.
WoodGlue
Explorer
Aug 06, 2013
Put in bleach, make sure the tank is full and let it sit this way for at least 24 HOURS before rinsing.

WoodGlue

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