how much bleach for clean water system in RV?

Does anyone know how much bleach should be put in a RV water system to clean it out overnight? They would like to clean it out over night in about 6-12 hrs. They have a 6 cubic square ft water tank for drinking water. have read they can put as low as .75 cups of bleach in the system to clean it but i read u can do 3.5 for our volume.

I am asking this for my son and his buddy that are in another state. I don't know the answers and I don't have an RV but I thought you guys might be able to give some good help. Thanks

 

I don't know the answer either but I would use no more than one ounce per gallon of water IF you are able to fully drain and flush the water tank. If you cannot fully drain the tank then I would use no more than 1/2 an ounce per gallon and maybe only 1/4 ounce per gallon. A tank that has dimensions equaling 6 cubic feet has just a touch under 45 gallons ultimate capacity.

 

In our motorhome we use 2 ozs. of bleach per 15 gallons of water.

We mix the bleach and water in a gallon jug and pour it into the tank. Then we fill the tank just about full with water. We drive around for 5 minutes so that the mixture sloshes around inside the tank and cleans all the areas. Fire up the DC pump and allow the chlorinated water to flow thru all the sinks ...hot and cold.....toilet, and any outside faucets. Allow solution to remain in the system for 4 hours.

We drain the system completely. Then we refill with fresh water and drive around again for 5 minutes. Flush all locations again and then drain the tank completely.

Never had any problems.