Thursday, June 1, 2023


Have you ever had your RV’s black water tank professionally cleaned?

Oh, the black water tank—the pit toilet of RVs. Actually, they are more like a pit toilet than a home toilet, where you flush and whatever is in the toilet begins an underground journey to the local sewer treatment plant.

With an RV toilet, you flush and the contents drop straight down, or through a plastic pipe that descends slightly and eventually deposits the contents into the black tank. When the tank reaches a certain level, you head off to a dump station, attach a special waste hose to a disposal valve, open it, and the contents of both the gray and black tanks flow into the RV park’s sewer system. It’s just like magic! Well, sort of…

But sometimes there’s a problem. Not everything in the black tank flows away. It gets stuck. It attaches to the bottom or side of the tank. You can flush it out with various devices made for that purpose, but they are not 100 percent effective. And if the situation gets bad, the tank can get plugged! And, no, putting ice cubes in the black tank and then driving your rig over bumpy roads is not effective—contrary to what YouTube experts say.

That’s when you summon the local RV waste expert. He has the high-powered hose and other equipment to clean the tank so clean that you could eat off it. (Yuck! We’re kidding about that, of course!)

So, our question today is, have you ever had your black tank professionally cleaned?


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8 months ago

We haven’t yet. After 6 years of full time use – which is better than parking and letting a tank dry out, we plan to have the tank cleaned during out winter season in Arizona.

Jeff Craig
8 months ago

Since the toilet in my Class A is basically over the dump valve, we don’t have any issues with holding tank smells. Using the new TST Orange treatment and cleaning it at the start and end of every season prevents problems..

Kurt Shoemaker Sr
8 months ago

I dump the black tank at the campground. My wife dumps some water and laundry detergent in before we leave for our next destination. At the end of the season, or if I know I won’t be using the black tank for a period of time I will tow my 5er up to a Rest Area located a couple miles from my home. They offer a “free’ dumping station which has water. I flush out my tanks using the sprayers inside the black tank and let it flush out until clear water is flowing. I’ve never had a problem with my black tank using this method.

8 months ago

With proper care we have just never had holding tank issues.

We purchased a used TT for our daughter’s family that had been used as a permanent and the owner just left the tank drains open. Let’s just say the black tank was in really bad shape and half full of caked “residue.” I dumped in bacterial digester and filled with water to the top. Let it sit for a full week. Emptied and flushed and it was like new. The gauges even functioned correctly.

Tank management isn’t rocket science!

Last edited 8 months ago by Spike
Neal Davis
8 months ago

I really wanted our tanks professionally cleaned, especially the black tank. I did not because we were never in Arizona or Florida, where the companies seem to be. Our 40-gallon black tank filled very quickly. Part of the reason was the commodes used lots of water to flush even using the small flush. I think the tank also had a layer of hardened stuff on the walls or bottom that repeated flushing failed to loosen. [We bought the RV new but it had sat in the Texas sun for at least 12 months.]

Bob Weinfurt
8 months ago

I just quickly pour a bucket of water down the toilet after the tank has emptied. My G/F watches the clear elbow and has told me that sometimes a few chunks come out. My rig is old and has never had a problem.

8 months ago

For me the most important thing to do is be careful what you put into your tanks in the first place. For the gray tank, we make sure that we wipe all plates, greasy pans and etc off before washing. We also use a screen in the sink drain to catch almost everything we missed. Use of Dawn dish soap is suppose to help break up scum and grease (at least that’s what they advertise) and also a tablespoon of Rid-ex after every dump. For the black tank I always keep Rid-ex in the tank and plenty of water when flushing and sometimes dump a gallon of warm water down to break up the waste at the entry point of the tank before dumping we also use the black tank rinse system a few times after every dumping. For the drive we put a few inches of water in both tanks with Borak and Dawn to slosh around. Very seldom do I have an issue with tank gauges not working. I just bought a flexible scope that plugs into my cell phone to inspect both tanks and they appear to be be very clean.

Mel S
8 months ago

I usually attach my garden hose to the black water flush and rinse it numerous times with “hot” water. This cleans the tank really well. I normally do this once a year. As well, I have put Calgon dishwasher detergent in the black and grey water tanks and then fill them 1/2 way up and then drain the tanks when I get to my destination. This also works quite well.

Bob p
8 months ago

I never let it go to that point, every time I empty the tank I let the flushing washers run for 30 minutes, you’d be amazed at the “stuff” left in the tank after draining it. Small pieces will still be coming out 20 minutes after you start the flushing process. After 30 minutes the water is running clear.

8 months ago

I have had mine done once, when I bought our slightly used MH. After cleaning myself, they did the cleaning and used a high pressure type washer/Vacuum that produced even MORE nasty stuff. They say every 1-2 years its a good idea to have it done, depending on use. I keep up with normal solutions and cleaning products as learned from the professionals here. My issue now is that there is no one locally in my area to do so. I think it would be a good idea for RVT to put an article with references together with the info. IMHO of course.

8 months ago

Had grey water and black tank done at the same time at a rally. Made a huge difference in the grey water tank as I was already diligent about flushing the black. Found out the black chunks coming out of the grey tank was not good.

8 months ago

Never considered having it done. Not a current problem.

Larry Lee
8 months ago

I have given up on getting our indicator lights to work so why would I get the tank cleaned. I am certain we would be back in the same situation within a week.

Tommy Molnar
8 months ago
Reply to  Larry Lee

I tend to agree, Larry. Most, and I mean most RV gauges are useless. You just have to get used to how often you need to dump depending on use.

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