another sanitizing question

[CHICKDOE]

we have to keep the trailer at a storage lot with no power, water hook up, or sewer dump. we will be going on our first trip to a full hookup rv park in a few weeks. the trailer has been winterized with antifreeze, but none in fresh water tank. I would like to sanitize the fresh water tank. from what I read you add 1/4 cup bleach per each 15 gallons of tank capacity and then let it sit for 24 hours. our fresh tank is 70 gallons so 1 1/4 cup bleach seems ok.

our trailer only has a single fresh water input port with a valve that is used to direct the incoming fresh water to either the fresh water tank or bypass the tank and direct the incoming water directly to the various water lines. (ie city water). when we get hooked up at the rv park we will be using the city water option. can I then disconnect the city water hose and switch the valve to direct water to the tank. I can suck up the bleached water using the winterizing port to get bleached water into the fresh water tank. afterwards I can again switch the valve to city water and reconnect the city water hose. at this time I should have bleached water in the fresh water tank which I can let sit for 24 hours to do the sanitizing while still having city water flowing through the plumbing. if I keep the water pump off the bleached water should not migrate out of the fresh water tank.

do you see any problems with this?

[Flybob]

There are a few problems with your solution.
1. The winterizing port is on the inlet side of the water pump and will be OK at adding bleached water from the container the winterizing hose is in into the RV water lines, but will not add water to the FW tank.
2. You should really sanitize the fresh water lines as well which means the bleach water should sit for some time in the plumbing lines.

Best solution
1. Drain antifreeze from lines
2. Connect city water to RV and choose fill FW tank setting and add some water to FW tank.
3. Disconnect city water hose and drain. Pour your bleach into city water hose.
4. Reconnect then continue to fill FW tank.
5. Disconnect city water and turn on water pump and run faucets until bleach water ( smell it) comes out each one.
6. Let sit for 4-12 hrs.
7. Drain FW tank refill and turn on water pump and run through plumbing until no bleach smell.

[CHICKDOE]

to flybob, thank you! this makes sense. if I put the bleach into the tank and lines just before going to bed we could let it sit all night. only water that would be used would be toilet and the bleach won't hurt that. first thing in the morning flush it out. seems pretty simple! would this work?

[Flybob]

That would work but where would you drain the FW tank 70 gals on the ground would make a mess. Other option would run all 70 Gals thru system and into holding tanks. Hope you have full hook up.

[CHICKDOE]

we'll have full hookups. so I could pump into the holding tanks and out the sewer hose. or I have added a fitting on the fresh water drain that has a male garden hose fitting. I could attach the utility hose and just run it over to the sewer drain and not use the pump. I appreciate your shared knowledge.