Tuesday, November 28, 2023


What keeps holding tanks clear? Readers offer ideas

Did you read my story last Sunday about the “pyramid of poo” in my RV’s black tank? You know this is a hot topic of conversation among RVers. No sh*t! Read it here before continuing on.

I received some good responses from readers who don’t agree with everything Kleen Tank literature says. Several swear by Dawn or Happy Camper. No one mentioned the products you find in an RV store aisle. Not all agree you need to spend $250 every year on a professional service but all agree that the No. 1 thing you can do to keep your tanks flowing is water, water, and more water.

That’s going to be tough for me because even though I have a 28-foot motorhome, my fresh water tank is only 27 gallons, my gray water tank is only 23 gallons and my black tank is a decent 35 gallons. Wow, too small if you’re not an avid RV park fan, and I am not! I have a backwash system but I am not convinced how great that is.

Readers speak out: What works and what doesn’t work on their RV black and gray tanks?

Reader Randall S. recommended the Camco RV holding tank rinsing wand for cleaning tanks periodically. So did someone named OM, who added, “I don’t see anyone mention using ‘The Wand’ in black tanks. For me, it’s part of routine maintenance, once a month or so when we are in the rig for the winter. Usually, the sensors will work again for a while.”

Rod just uses a plain old rubber water hose. But then he has a window in his bathroom—I don’t. He writes, “I use a lot of water. Put a rubber water hose from outside through the window into the toilet. Turn on the water and let it run. Load the tank with water, load the toilet with water, flush, load until the water is clear coming from the black tank.”

For gray tanks, my pal Diane N. says: “I paper towel wipe dishes before washing them and avoid letting much organic food waste down my sink.” Great idea! She added: “And now I’ve added Pine Sol and Calgon to my shopping list…”

Robert says the Kleen Tank recipe didn’t work for him. “After attending a manufacturer-based rally at Elkhart, we tried the Kleen Tank recipe and double flushing for several months. Sensor function got worse. Tried Boraxo and Dawn. Boraxo stops ants but has no effect on sensor function. Tried lots of water. Less expensive but odors returned. Now re-evaluating Happy Camper. What works for us: Double flush. Add about 5 gallons of water per tank after dumping. Happy Camper reduces/eliminates grey tank odor. Add enough water, etc., to tanks to about 2/3 then dump when leaving a campground. 100 miles of sloshing loosens a lot. Dump again on arrival if black tank flush is convenient.”

I like the idea of sloshing!

Gregory is also a Happy Camper fan. “It just works; no smell and it breaks down solids to liquid. There are some incorrect statements in your article, as well. Possibly, Kleen Tank is drumming up business like the quick lube companies, who say to change oil every 3,000 miles; I won’t go there. Just follow the manufacturer’s recommendation.

“After over 40 years of RV boondocking, I’ve never had solids stack up. A process that works:

  • Fill the bowl with some water, about 2 inches
  • Place a piece of RV toilet paper on top of the water
  • Do your duty and flush. The paper will clean the bowl as it descends.”

Gary G. has a video suggestion: “Check out the ‘Wandering Wagners’ YouTube video ‘I’m Shaking’. They suggest using a product called Commando Tank Cleaner for messed up tanks.”

IM swears by “Happy Camper, Dawn, Borax has worked for years without issue. We use I’m Septic Safe TP, same that we use in our Stix & Brix system.”

Why does everyone recommend Dawn and not, say, Palmolive? Well, for one thing, it is rated the No. 1 dish soap by the Good Housekeeping Institute Cleaning Lab. “Dish soap is one of the only products gentle enough to be used in a variety of capacities without damaging different materials or surfaces. That said, it is still definitely strong enough to get the grease-busting job done.” It’s also been tested on birds covered in oil and removed 67 percent of the oil as opposed to 55% or 33% by other brands. (www.csef.usc.edu)

Valerie O. recommends a product I haven’t heard about: “I also inherited this problem with the used RV I bought (suspect poor habits and leaving it dry while it sat before sold). After trying many other things, I paid $250 to the RV Proctologist and accomplished nothing. Finally added ‘TankTechsRx for Plugged Black Tanks’ and plenty of water. Drove home, let it sit over the summer, and drove cross-country before I emptied it. Finally, no more problems and I have so much more capacity now.”

I think we all know not to flush facial tissue down the toilet. That is, everyone but Bob P’s friend. Here is a cautionary tale. “My friend had a recent surgery with an open draining wound he had to clean several times daily. He casually dropped Kleenex down the toilet after using it to clean the wound. Several days later he attempted to dump the black tank, it was plugged with undissolved tissues. He finally got the plug broke loose and drained the tank by drilling a small hole in the clear plastic elbow and putting a stiff wire through the hole and breaking loose the ‘dam.’ Then plugged the little hole with epoxy.” Wow, I think this gentleman learned his lesson.

Lesson concluded!

FYI, I am “sticking” to the recipe of Calgon bath beads and Pine Sol recommended by Kleen Tank. After all, I bought it and I am gonna use it!

OK, our lesson on gray and black tanks is now concluded. Unless you have something to add?

Oh, one parting shot: What did one toilet bowl say to another toilet bowl? “You’re looking flushed.”


Jan Steele
Jan Steele
Former newspaper editor Jan Steele started her career in third grade as a school correspondent for her local newspaper and has been writing for publication ever since, including a 30-year-stint at the Herald-News in Joliet, IL. She decided in fourth grade she wanted to hit the road as soon as she could—and retired eight years ago to RV full-time.



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Larry (@guest_259018)
27 days ago

Instead of Dawn which tends to foam up a lot when we “drive and slosh”, I use dishwashing detergent (Cascade) which does not foam and so it rinses out faster.

Neal Davis (@guest_258900)
28 days ago

Thank you, Jan. Nice parting comment, too. 🙂

Bill (@guest_258824)
29 days ago

Odors are usually due to the vents being clogged or otherwise ineffective. Chemicals do little or nothing to help the situation. Use common sense in not putting anything down the drain that won’t dissolve, including grease and cooking oil. Otherwise normal use with adequate amounts of water will keep everything flowing fine.

Earl Balentine (@guest_259234)
24 days ago
Reply to  Bill

One of the things that happen is when the gray tank is full and you pull the dump tank valve open fast it, the gravity of the water going out pulls the water out of the P-trap and then shortly after that the smell gases rise up thru the sink drain. best to open valve very slowly like you are suppose to so when opening your propane tank valve. As soon as you dump your gray tank beside to run some water in your sink to keep the P-trap full.

Lynn (@guest_258814)
29 days ago

We have been using the camco cleaning wand which has worked great, unfortunately the last time I used it the whole flexible end fell off in the tank. We haven’t worked out how to retrieve it yet. Any suggestions?

Gary Bate (@guest_258744)
29 days ago

I just throw all the pebbles and rocks my wife collects into the toilet and drive like a maniac. Works great !!! Lucy, we don’t need more rocks!!!

John Hicks (@guest_258735)
29 days ago

I came across a reference on rv.net from 2012 or so in which the Pine Sol manufacturer responded to a query and told the questioner to not use Pine Sol in RV tanks. Evidently the Pine Sol and Calgon fad comes from one tank-cleaning company.

Janette lynn Steele (@guest_258907)
28 days ago
Reply to  John Hicks

John: Well that is scary. Kleen Tank has been around for some years with this recipe and there must be more than a thousand RVers out there using that formula. It is just 4 ounces so that’s not a lot for a 30 gallon tank?? I had not heard this.

Drew (@guest_258732)
29 days ago

Just so you know: Happy Camper is not available in California.

Earl Balentine (@guest_259235)
24 days ago
Reply to  Drew

I use to use Happy Camper but California made it illegal to use and some RV Parks doesn’t allow it in their septic tanks. Happy Camper has cancer causing chemicals and it’s not safe for the environment.

Cookie P (@guest_258671)
29 days ago

I have not read anything on RV Travel about “Liquified” by Matt Foxcroft of Matt’s RV Reviews. Youtube and my FB RV groups are filled with praise for this product. I don’t have an RV yet but wonder if the praise is just hype or if RV Travel readers are hesitant to try something new if they already found something that works.

Cynth (@guest_258808)
29 days ago
Reply to  Cookie P

I tried it. Had been using happy camper for the most part. I was disappointed. It didn’t “liquefy” for one thing and a smell started. Don’t get smells with happy camper and it does seem to liquefy for most part. I also sometimes add a bunch of dawn.

Earl Balentine (@guest_259237)
24 days ago
Reply to  Cookie P

I bought Pat’s “Liquified” recently and will be trying for the next couple months. My sensors have never been accurate since I bought our RV new in May 2023, I have tried all the different home remedies and RV store chemicals. Nothing has helped my sensors to read properly. And yes I rarely drop TP down the toilet and always leave the black tank 1/3 full of water on the last dump. We camp 1 week out of every month so it’s not setting and drying out. I have used the Camco Wand down the toilet several times, I also have Flush unit that attaches to the dump outlet. I use the black tank Saniflush and let it run for 30 minutes on while dumping several times. I will keep trying new chemicals.

Jim Johnson (@guest_258624)
30 days ago

We love our 2017 34′ TT. The one shortcoming is way too small bathroom gray & black holding tanks. I am emptying them every other day and there are just the two of us. The RV is also seasonally stationary so ‘rock & roll’ to loosen crud doesn’t work.

We use plenty of water. And lots more water via built in tank flush when emptying. I have tried most chemicals, including Happy Camper. I use a enzyme & deodorizer tablet, until the 1/3 sensor is ‘stuck’. A Commando tablet or two helps, but eventually (3-5 weeks) I pull out the extra hose (with vacuum breaker) and bring the Camco flex wand in through the door and over to the toilet. Takes 15-20 minutes to blast things clear.

Jim Johnson (@guest_258626)
30 days ago
Reply to  Jim Johnson

About that water usage. Potable water is a precious commodity in may places. I am confident our RV consumes far more water for the toilet than our residential system. I get it the current RV is relatively cheap to install, but factoring in the cost of the water? I am waiting for the RV industry engineers to come up with something better that still ties to a campground septic system.

Carol (@guest_258741)
29 days ago
Reply to  Jim Johnson

Maybe they could use the grey water to flush the toilet.

Earl Balentine (@guest_259242)
24 days ago
Reply to  Carol

They could but not cost effective for the RV manufactures. Some expensive RV’s recycles the gray.

Earl Balentine (@guest_259239)
24 days ago
Reply to  Jim Johnson

A residential toilet uses 2-3 gallons to flush and RV toilet uses 1-2 quarts of water to flush.

Earl Balentine (@guest_259238)
24 days ago
Reply to  Jim Johnson

Never empty your black tank until it is full, the gravity of a full tank helps to push everything out. If your tank is 1/3 full on last day of camping be sure to fill the black tank at lease 3/4 full then dump.

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