Have you seen the hot iRV2 Forums discussion about whether or not the USI RV gray water recycling system is a useful RV mod – or a smelly one to avoid?
In “Recycle Grey Water!” iRV2 member Freebird1958 asks:
Hello, fellow boondockers! I am asking if anyone has consider or installed the Recycle RV Gray Water Kit? This diverts the gray water from showers and sink water and filters it for toilet use. Any information and ideas are appreciated.
Freebird1958 is talking about the Extend Your Stay Tank Saver Kit, a RV mod which allows you to divert filtered gray water into your RV’s black water tank. In return you:
- Save fresh water for better uses, like drinking
- Reduce inflow into your gray water holding tank
- Extend your dry camping days by avoiding a dump station trip
Most forum members who replied to Freebird1958 were leery about the mod. In addition to having a fear of clogging the RV’s water filter, the majority of respondents said they worried about the odors that would come from putting gray water into the toilet bowl:
For example, dagmandt said:
Have you smelled the grey water? Ew…. I wouldn’t want it sitting in my toilet bowl. We had a vent issue in our bathroom and we were sure it was the black tank it stunk so bad. Nope, was the gray water tank.
Avoid Smelly Recycled Gray Water and a Clogged Water Pump
As an experienced RVer and engineer, the designer of Extend Your Stay Tank Saver Kit, Greg Corwin, has taken these risks into consideration when designing the system.
Here’s how he circumnavigated the risks:
- By designing the system so that it utilizes a secondary pump which won’t affect the operation of your primary fresh water pump.
- He incorporated a premium carbon-wrapped filter that won’t restrict water flow but will help take away the particulates that can cause odors emitted from your gray water tanks.
- Corwin educates buyers about the importance of preventing stinky, bacteria-causing odors in the RV gray water tank.
Whether or not you opt into the gray water recycling system, keep in mind that every RV should instill these good dry camping habits to avoid a rotten egg gray water tank smell. For example, Corwin explains that we should:
- Use a paper towel to clean all food debris from plates and cookware before washing in your sink.
- Purchase mesh drain covers to prevent large food particles from going down the drain.
- Only use your bathtub and sink for their intended purposes. All other waste should be put in the black tank through the toilet.
RV gray water recycling isn’t for everyone. But if you love to dry camp and want to avoid trips to the dump station, this system could be perfect for you. It works best with RVs that have equally sized gray and black water tank holding capacities, since it will move gray water into your black tank in order to leave more room for showering and dish washing.
To learn more about the USI Extend Your Stay Tank Saver Kit, catch this December 2015 iRV2 Blog post, “RV Grey Water Recycling Made Easy.”

Often called “The O.G. of full-time RVing,” Rene Agredano and her husband Jim Nelson hit the road in a fifth wheel trailer in 2007, after their dog Jerry lost a leg to terminal cancer. Sixteen years later they are still traveling and sharing their nomadic adventures at LiveWorkDream. As a self-employed wordsmith, Rene shares her expertise for many RV industry videos, publications such as the Escapees RV Club Magazine, and has authored numerous books, including the Essential RVing Guide to National Parks, and Income Anywhere, a guide to earning money on the road. She has been featured in global media outlets including the PBS documentary “NATURE: Why We Love Cats and Dogs,” The Guardian Sunday Edition, and the Dan Pink book Free Agent Nation.
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