Dissolve 2 cups of powdered water softener in 1 gallon of hot water and pour it down a drain in your RV. Powdered water softener is found in the laundry section of the grocery store. Pour 2 tablespoons liquid dish washing soap down the drain. Run the water in your camper until the gray water tank is three-quarters full. Drive the RV around for a few minutes to agitate the solution in the tank, then drain it completely. Thoroughly clean the gray tank in this manner at the beginning of each season.
Maintain the gray tank by adding 1 cup of vinegar for every 10 gallons in your gray holding tank. For example, if your tank holds 40 gallons, and the sensor reads one-quarter full, you have 10 gallons to treat in your tank. Check and treat your tank once daily. Vinegar is a natural, safe disinfectant that kills germs and cuts odors.
Empty your tanks after each trip. Start with the black holding tank, followed by the gray tank. The gray tank water along with the vinegar flushes the pipes clean. The vinegar also removes any sediment that has accumulated on the holding tank sensor, and will improve the accuracy of their readings.
