Can I use the GEO method of keeping my holding tanks clean?

The GEO method is a mid-1970s sort of “home-brew” method of keeping your RV’s waste holding tanks clean. The basic idea was to create a mixture of Borax (a water softener), Calgon (or another detergent), and bleach (along with water, to dilute the mixture). This was used as a tank additive in lieu of enzymes, bacterials, or harsh chemicals, such as formaldehyde.

The basic concept is sound, however, Borax is a very harsh alkaline chemical that can corrode metal parts (such as the sensor nubs in your tanks). Detergent should be avoided in black tanks (it’s hard to not have it in your gray tanks!) as it can reduce the slipperiness of plastic holding tank surfaces over time. Finally, bleach is highly corrosive and will eat away soft rubbers and plastic, such as are found in your tank’s valves and seals.

A better option to Borax is Calgon, which is not nearly as corrosive. Adding Pine-Sol or another pine oil cleaner to the solution is preferred, as it has disinfectant qualities and strong odor-masking properties. For the “recipe” to formulate your own tank additive, please visit this link.

By the way, that’s a geode in the picture!