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RV Grey Water Versus RV Black Water: The Same, But Different

If you’re new to RVing and worried about a dump station disaster like in the movie “RV,” it’s time to face your fears. Learn how to make friends with your RV waste water holding tanks by understanding the differences between RV grey water versus RV black water tank needs.

Learn to make friends with RV waste water.

RV grey water versus RV black water
Rene Agredano

RV Grey Water Versus RV Black Water Basics

  • Everything that goes down the kitchen sink, the bathroom sink and your shower is called “Grey water.” Somewhere in time, RVers probably thought that calling this waste water “grey” would imply that this water is relatively harmless.
  • Everything that gets flushed down the toilet is called “Black water.” Since coming into contact with toilet waste is relatively hazardous to your health, it was a smart choice for early RVers to describe it as “Black” water.

RV grey water versus RV black water seems like a simple concept, doesn’t it? After all, we have the same kind of waste water in a typical domestic stick home. But that’s where the similarities end. Your house on wheels can’t take care of domestic waste water like a stationary house.

Instead of sending your waste down to the city sewer treatment plant each time you rinse a dish or relieve yourself, in an RV you are sending that byproduct into a holding tank underneath your feet. And if you’re not careful, that holding tank can collect bacteria that reeks, attracts bugs and stinks up an entire RV park.

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Here’s how to make sure that doesn’t happen:

RV Grey Water Tank Tips

  1. Clean all food scraps before washing dishes. Take time to clean your plates, pots, pans and utensils before dish washing. This ensures that food waste doesn’t go down the drain, collect at the bottom of your gray water holding tank, and help grow rancid bacteria colonies.
  2. Use a sink strainer in the kitchen and bathroom. If some food bits go down the kitchen sink, a good wire mesh sink strainer can capture them. A tub strainer in the bathroom will help prevent hair from clogging up your sewer valves.
  3. Keep your gray water tank clean. Clean RV gray water tanks don’t smell, attract bugs or get clogged. Maintain a clean gray water tank by occasionally rinsing with a homemade “Geo” cleaning method.

RV Black Water Tank Tips

  1. Don’t use your toilet as a trash can. Don’t flush pills, cotton swabs, hygiene products or anything else that isn’t manufactured by your body. These objects will clog your sewer drain and result in a messy heap of sludge that eventually requires a professional RV proctologist to remove it.
  2. Use TP sparingly. RVers have all sorts of RV toilet paper advice. Some say single ply is better for tanks while others swear it doesn’t make a difference. Whatever you decide, be conscientious about how much TP you use to avoid excessive waste pileups in your black water tank.
  3. Use lots of water in the tank. Adding a few gallons of fresh water into your newly emptied black water tank will help break up solids that can clog the valve. The extra water will also slosh around the tank while you’re driving and do a good job cleaning the sides.

You don’t want to call this guy.

RV grey water versus RV black water
Rene Agredano

Carrying around your own human waste inside your rolling home takes some getting used to, but following this common-sense approach will help you avoid the ugly side effects of poorly maintained grey and black RV waste water holding tanks.




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