One of the most common discussions among RVers is how to properly deodorise and clean holding tanks. While some campers swear by their preferred commercial brand of tank chemicals and deodorisers, more environmentally sensitive RVers choose to make their own tank treatments. These homemade treatments are cheaper and friendlier to the planet, since they use no harmful additives such as formaldehyde.
The Geo Method
A popular recipe for making your own holding treatment is called “The Geo Method.” This is based on using water softener, a product that breaks up solids which accumulate from hard water, such as soap scum. By using water softener in your waste water tanks, it will loosen up solids that stick to the sides. The more you use it, the slicker the walls of your tanks will be. When you empty your tanks, solids will easily rinse away. The lack of solid build-up inside, along with the addition of household bleach, will eliminate tank odours completely.
Geo Method ingredients are found in the laundry products aisle at your local grocery store. There are just three products you'll need to purchase: water softener, powdered laundry soap and household bleach. Most RV systems will require about two boxes of softener.
The best time to make the Geo Method treatment is when you have access to hot water, and immediately after dumping your tanks. You can make and use homemade holding tank treatments the same way you would any other commercially available products.
Cleaning Your Tanks
When your RV tanks are empty and the valves closed, take two cups of water softener and dissolve it in a one-gallon bucket of steaming hot water. Pour the mixture down the drains in your kitchen first, then into your bathroom sinks. You'll pour it down the toilet last, and follow by pouring one cup of washing powder into the toilet tank.
The addition of laundry soap in the toilet tank will provide extra cleaning action. You won't need to put laundry soap in the grey water tanks because these tanks regularly get enough detergents in them to help loosen solids along with the water softener. You can leave this mixture in your tanks until they are full again.
As a last step, add a small amount of bleach to your holding tanks, which will kill accumulated bacteria from waste water. Because bacteria causes odours, the addition of bleach will eliminate any unpleasant smells resulting from normal use. You can add it when the tanks are about halfway full, and continue using your RV as usual. Repeat this method each time you empty your tanks.