A lot of RVers leave their gray holding tank pulls open. Is this a great or even good idea? You may not think it’s a big deal, but you could be asking for trouble. Read on to find out why.

This may seem obvious, but NEVER leave your black tank gates or pulls open while you are camping or using your RV’s holding tanks. We should all know that. But what about your gray tank’s pulls?

What’s wrong with leaving your pulls open?

When your holding tank release pulls are open, the tank’s contents are evacuated through your RV’s waste system and out the sewer hose attached to your RV. When your tanks are 90% to 100% full, the liquid forms a vortex in your tank, helping to wash away all of the waste material inside. A full tank empties better than one that is a third or half full.

But leaving a tank pull open allows water or liquid to seep out, leaving any solids behind. In a black tank, that means human waste and toilet paper pile up, creating a mound that will soon clog your black holding tank and cause a back up in your waste system. Yuck!

But there’s no waste in your gray tank

That’s not exactly true. Your gray tank contains soap, grease, food waste, hair, and other stuff that washes off of you at the sink or during a shower. One time, that all starts to stick together into clumps. Plus, your gray tank is the perfect environment for mold growth, especially slime mold.

By leaving your gray tank’s pull open, the water or liquid drains out, leaving this debris behind. It’s not as dire of a situation as leaving your black tank’s pull open, but it can still cause a stinky gray holding tank and even cause build up over time.

When you can leave your gray tank pull open

What about doing laundry in a clothes washer? Even low-water use washing machines can create a fantastic amount of waste water. It’s okay to leave your gray tank’s pull open when doing laundry.