Hook Up Right: Water & Sewer Tips for Every RVer
Betty Grant - RV Pocket Tech • May 8, 2026
One of the first things most of us do when we pull into a site is get hooked up—water hose on, sewer hose connected to that lovely dump port, and we’re off to the races.

But here’s something a lot of folks skip (and yeah...we’ve all done it): running the water before hooking up to the RV.
That first couple seconds of water coming out of the spigot and hose? It’s not exactly what you want going straight into your fresh water system.
It’s been sitting in there, getting warm, picking up whatever it wants along the way. Takes about 2–5 seconds to clear it out.
Do yourself a favor—let it run first.
While we’re talking water, that basic blue filter you grab at Walmart or Amazon? It’s not a bad idea at all. It’s a simple layer of protection.
If you want to step it up, there are more advanced systems out there—multi-stage filters, softeners, even reverse osmosis setups—but the little blue one is a good start.

Now let’s talk about the part nobody enjoys—the sewer hose.
The “slinky.” You’ve got to hook it up, but what you do next matters more than most people realize.
A common mistake? Leaving your black tank valve open all the time.
Seems convenient, but it’s a bad move.
What happens is the liquids drain out, and the solids stay behind...
building up into what’s called a "poop pyramid". And trust me,that’s exactly as fun as it sounds.
Another common mistake, one we see a lot—pulling both gray and black tanks at the same time. Don’t do that either. You lose the ability
to rinse things out properly, and it just doesn’t work the way you think it does.
While we’re at it— the same idea applies to your gray tank.
A lot of folks leave that one open too, thinking it’sharmless. But that can let sewer smells creep back up into your RV, especially when you flush or run water.
It can also invite sewer flies...which nobody wants hanging around the kitchen sink.
Keeping the gray tank closed helps hold water in the tank, creating a barrier and giving you a good flush when youdump it.
Again—liquid is your friend.

Here’s the bottom line: water is your best friend when it comes to your tanks. Especially the black tank. You want plenty of liquid in there to keep everything moving the way it should.
Not enough water + too much toilet paper =problems you don’t want to deal with.
Simple rule of thumb:
- Run water for a few seconds before hooking up your hose
- Keep your black tank closed until it’s ready to dump
- Keep your gray tank closed to prevent smells and sewer flies
- Dump black first, then gray to rinse the hose
- Use plenty of water every time you flush.
Betty GranT is the voice behind RV Pocket Tech, a resource dedicated to helping RVers get the most out of the technology, tools, and systems that make life on the road easier.
She & her husband share a passion for practical, no-fluff advice and a knack for making the technical feel totally doable, Betty has been helping RVers work smarter—not harder—for years.
Whether it's water filtration, tank management, or the gadgets that make campsite life smoother, she's been there, tested it, and has the stories to prove it.
This is her first of many contributions to the Learn to RV community—and trust us, you'll want to stick around for more.
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