You should add a 1/c cup of clorox in the water tank.
If non-toxic RV antifreeze was added directly to the fresh water holding tank when the unit was winterized, the first step is to drain any remnants of antifreeze from the tank. Next, add potable water to the fresh water holding tank, turn the water pump on and open all of the water faucets. When you see clear water running through the system, turn off the pump and close the faucets.
Make sure you run fresh water through the entire plumbing system to include the outside shower, toilet, ice maker and washing machine, if applicable. Take the water heater out of the “by-pass” mode, if applicable. If the water heater wasn’t bypassed, the antifreeze needs to be drained from the water heater tank and collected in a bucket or other container. With all traces of RV antifreeze removed, you can reinstall any water filter cartridges that were removed for winter storage. The antifreeze that was in the plumbing system is now in the gray and black water holding tanks and will need to be emptied when you have access to a suitable waste disposal site.
Sanitize the RV water system so it is safe to use:
Make sure all of the drains are closed and drain plugs are installed. Take a quarter-cup of household bleach for every fifteen gallons of water your fresh water tank holds. Mix the bleach with water into a one-gallon container and pour it into the fresh water holding tank.
Note: If your RV does not have a fresh water fill location, you can pour the bleach solution directly into a potable RV drinking hose that is connected to the RV prior to connecting the other end of the hose to a potable water supply. Fill the fresh water holding tank completely full of water. Turn on the water pump and run water through all hot and cold faucets until you smell the bleach. Close the faucets and let the solution sit in the water tank and water lines for twelve hours. Drain all of the water and re-fill the tank with potable water. Turn the water pump on and open all faucets, running the water until you no longer smell any bleach. It may be necessary to repeat this process to eliminate all signs of bleach.