Thread Tools Search this Thread Display Modes
Old 10-29-2018, 10:02 PM   #1
Winnebago Owner
Join Date: Sep 2018
Posts: 71
Tank Cleaner

Just wondering if anyone has any knowledge of this.

I recently got a tip from an RV service writer to pour a half bottle of liquid fabric softener into half a tank of clean water in blk/gry tanks and drive around for awhile to clean them. He said it is not harmful to the seals.


R2D2 is offline   Reply With Quote
Old 11-05-2018, 05:51 PM   #2
Winnebago Master
SarahW's Avatar
Join Date: Oct 2011
Location: Houston TX
Posts: 881
People put all kinds of cleaners in their tanks with varying degrees of success. The fabric softener certainly wouldn't harm anything... but I don't know if it would help, either.
SarahW is offline   Reply With Quote
Old 11-06-2018, 05:58 AM   #3
Site Team
ThomB's Avatar
Join Date: Feb 2017
Location: Pinellas Park, FL
Posts: 532
We don't use anywhere near that much but on shorter trips between parks we will use 1 CUP of Calgon and 1 cup of liquid dishwasher detergent in each of the tanks along with a bit of water (also not a 1/2 tank normally).
Thom Boles
2010 Winnebago Vista 32K with a 2013 Mini Cooper S Roadster toad.
ThomB is offline   Reply With Quote
Old 11-06-2018, 10:02 PM   #4
Winnebago Owner
Join Date: Sep 2018
Posts: 71
Thank you for your responses. Just looking for advice and to not to make mistakes.

R2D2 is offline   Reply With Quote
Old 11-07-2018, 08:48 AM   #5
Winnebago Master
Ray,IN's Avatar
Join Date: Aug 2001
Location: North America somewhere
Posts: 697
I prefer clear water instead of spending money on doubtful products. Never had a tank issue in nearly 40 yrs of camping. Just make sure there is enough water in the black tank to cover ALL solids.
2000 Winnebago Ultimate Freedom USQ40JD, ISC 8.3 Cummins 350, Spartan MM Chassis. USA 1SG, retired;PPA,Good Sam Life member,FMCA."We the people are the rightful masters of both the Congress and the Courts - not to overthrow the Constitution but to overthrow men who pervert the Constitution. "Abraham Lincoln"
Ray,IN is offline   Reply With Quote
Old 11-11-2018, 11:03 AM   #6
Winnebago Owner
Join Date: Sep 2018
Posts: 71
Thanks Ray, I have tried just plain water when we changed campgrounds, but it didn't change the reading. Our gauge reads 2/3 all the time. It's been that way since shortly after we bought this coach. The dealer made the recommendation to try the fabric softener.

R2D2 is offline   Reply With Quote
Old 11-11-2018, 01:12 PM   #7
Winnebago Owner
Join Date: Mar 2018
Location: Martinsville, IN
Posts: 76
1. Does your RV have a black tank sprayer?

If so, I would turn the sprayer on and close the black tank valve. Let the black tank fill up, then dump. Do this several times.

I was amazed what came out after the 2nd and 3rd time of doing this. We did this a week ago as we were putting the RV up and wanted the tanks to be very clean for the winter.

If you do not have a black tank sprayer run a hose and point down the toilet til fill up.

I have heard Borax was a good thing to put down your black tank, however, I haven't used it yet but plan to next season.
jhedges is offline   Reply With Quote
Old 11-11-2018, 01:53 PM   #8
Winnebago Master
powercat_ras's Avatar
Join Date: May 2015
Location: Manhattan, Kansas USA
Posts: 854
Rain Drops water softener powder is half the price of Calgon and has helped in my RV when I apparently had crud on the side of the black tank that was causing the non-contact Winnebago OEM sensors to show a higher level than what was actually in the tank. I add about a cup to the black tank.
Randy - Manhattan, Kansas
2015 Vista 27N
2016 Honda HR-V
powercat_ras is offline   Reply With Quote
Old 11-11-2018, 04:16 PM   #9
Winnebago Camper
Join Date: Apr 2018
Location: Mesa, Arizona
Posts: 21
Grey tank gauges

Our also shows 2/3 all the time. Been this way for over a year of driving all over the country (we fulltime). This last drive I tried the new Thetford Tank Blaster Holding Tank Cleaner, 4-pack... ho humm... still nothing to write home about. I suspect the grease and oil in the dish water is my problem but without being able to get a spay hose in there (too many elbows and no direct access) we are only left with chemicals... I have wondered about something like jet dry... but have yet to give that a try.
PolarMike is offline   Reply With Quote
Old 11-11-2018, 04:30 PM   #10
David K's Avatar
Join Date: Nov 2006
Location: Grayson, GA
Posts: 344
Calgon in the tank

After you have cleaned the tank real well, you can add the Calgon with some water to the tank. What the Calgon does is that it coats the walls of the tank and makes them very slick so "nothing" will stick to them. I usually treat my black tank after 3 dumps and the grey tank after 5 dumps. I do not use it as a cleaner but as a lubricator. It does not harm your tanks nor your valves.
Dave and Karen -- '02 Ultimate Advantage 36 C, 350 HP Cummins, Allison 3060 Tranny
'13 Ford Edge, InvisiBrake
David K is offline   Reply With Quote
Old 11-11-2018, 05:52 PM   #11
Winnebago Owner
Join Date: Apr 2006
Posts: 111
Our gray water exterior tank sensors were not reading accurately. Just before leaving on a trip I added through the kitchen sink, and with water running, a whole bottle of Kirland (Costco) dishwasher soap and filled the tank with hot water by hose from the house. We drove 200 miles and let it sit overnight then drained the tank in the morning. The reading was nearly accurate. Then I started using only Dawn dish detergent for washing dishes, etc. after the dishes had been wiped of food using the paper napkins from the meal. I also wiped as clean as possible pots and pans. Before too long the readings were accurate and have been ever since I started and continue to follow this procedure.
2005 Adventurer 33V
2014 Honda CRV
Cheryl Bisson is offline   Reply With Quote
Old 11-11-2018, 07:38 PM   #12
2015 Itasca Spirit 27QP
Join Date: Sep 2018
Location: Milford, MA
Posts: 233
Look into converting to a See Level gauge system; a thousand times better than the standard tank level system. It's actually used on many of the higher-end RVs. I can tell within about a gallon of how full or empty my tanks are, including the propane which is extremely accurate.
JoeC is offline   Reply With Quote
Old 11-11-2018, 08:16 PM   #13
Im just another newbie
Join Date: Nov 2018
Posts: 5
Read this about cleaning black tank adding Ice

Written by : Paula Benzler-Wilkinson on RV Interior:Exterior Ideas, thought the ice idea was worth a try..,

We always empty our tanks where we are at before leaving. We also back flush the blank tank until the water that is being dumped is clear. We close the valves and we then add one cup of Liquid Calgon water softener (found at Walmart and other stores) to about one gallon of water and mix thoroughly. I use a cheap gallon pitcher found at a dollar store. We then pour it into our toilet (black holding tank) and add a 7lb bag of ice too. We mix another cup of Calgon with a gallon of water and distribute it evenly through the sink drains and shower drains. We add a bit more water down each of those drains. As we drive towards our next destination or home the sloshing cleans anything off of the walls and the Calgon helps remove any hard water deposits that may be on your tank fullness sensors . The ice aids in pulling anything of the black tank walls that may have been missed in the backflush. We dump when we get to our destination and then add a bit of water to the black tank and add chemical. If we are storing it, we just leave the solution in the tanks until we get to the RV park and then dump and add the bit of water and chemical. We live in central California so no worries about the tanks freezing. Never had any issues with our sensors after starting this process. Got this tip from a RV forum.
Bbrowne is offline   Reply With Quote
Old 11-11-2018, 09:25 PM   #14
Winnebago Owner
Join Date: Sep 2018
Posts: 71
Thanks all! Great tips. Our problem is with the grey tank. With all these suggestions I'm sure I'll find a solution. We're moving again this week and I'll check back in with our progress.

Thanks again,

R2D2 is offline   Reply With Quote
Old 11-12-2018, 07:39 AM   #15
Winnebago Camper
Join Date: Jun 2018
Posts: 11
On my unit I regularly use the Calgon and Dawn to keep the black tank clean. Many use the water softener with Dawn but couldn't say which is the best. But as stated by others that using the water softener wouldn't hurt.
dehnernc is offline   Reply With Quote
Old 11-12-2018, 08:56 AM   #16
2015 Itasca Spirit 27QP
Join Date: Sep 2018
Location: Milford, MA
Posts: 233
One more note... be careful what goes down the drain into your gray tank. Oils and fats will definitely leave a film on the sides of the tank which can disable the in-tank sensors. Powerful degreasers and enzyme tank cleaners may be necessary to get sensors back to operational. The See Level system has an external tank sensor and uses radio waves to sense the tank level. Yes, it does require access to the tanks and may be a chore to install (using the original sensor wires) but it works sooo much better.
JoeC is offline   Reply With Quote
Old 11-22-2018, 10:25 AM   #17
Winnebago Owner
Join Date: Sep 2018
Posts: 71
So I ended up using about two cups of fabric softener, a cup of liquid dish soap and between 1/3-1/2 tank of water in the gray tank. Took about a half hour, fifteen mile drive, with a lot of starts and stops to get some sloshing action. I was hopeful, but I can't say this exercise ended up change in the gauge reading. But it did leave better odor control for a few days; so we were happy about that. Guess I'll look into some of the chemical solutions now.

Thanks to all who replied with suggestions.

R2D2 is offline   Reply With Quote
Old 11-30-2018, 08:51 AM   #18
Winnebago Owner
danhannah's Avatar
Join Date: Nov 2014
Location: Washington State
Posts: 202

I have had the exact problem as you. Grey water tank problems only. I suspect oils and greases and my most suspicions are on coffee grounds. I tried everything chemical under the sun, more than twice, and no luck.

The final (and only) solution was mechanical cleaning. I removed the dump valve - surprisingly easy, held on to each tank by a rubber sleeve pipe connector. This is on a 27n where the grey water and black water join in a Y assembly.

I stuck a pressure washer wand up in there, and couldn't believe the gunk that came out, even after weeks of all kinds of chemicals and treatments. The gunk was a sticky crust made up of Dawn soap, Calgon, coffee grounds, commercial tank cleaner products, and oil and grease solidified into a wall-coating that was very strong.

After cleaning with the pressure washer, the sensors began operating correctly, and stayed that way for a year. But even with better caution on what goes in the drain, after a year, it is showing 3/4 full all the time. So I have to clean it again. I believe a regular hose will work, with a small diameter nozzle at the end. I'm not sure a pressure washer is required.

We currently use lots of Dawn, but no other tank chemicals. I will clean the grey water tank again mechanically, then start using a tank treatment of some kind and see if I can make it stay clean more than a year.

Best of luck.
2014 Itasca 27n
danhannah is offline   Reply With Quote
Old 11-30-2018, 11:16 AM   #19
2015 Itasca Spirit 27QP
Join Date: Sep 2018
Location: Milford, MA
Posts: 233
Have you tried any enzyme cleaners? Happy Campers comes to mind, available on Amazon. Otherwise, forget using the original tank monitor and upgrade to See Level tank sensors. I did earlier this year and unknown tank levels are a thing of the past. Installed properly, you can tell within a gallon or two what's in the tank and the LPG tank monitor is crazy accurate compared to the original. Yes, it is a bit of effort to install but it uses the original wiring. In my case, the water pump "On" LED and "Pilot Out" LED had to be rewired as they are powered by the original logic board which was removed. It's a bit un-nerving to cut the wiring harness and rewire to the new panel and I left enough wire on it to be reconnected if desired. I chose to remove the original faceplate and cut a hole in it to accommodate the new monitor panel; again a bit un-nerving. I am quite handy with electrical stuff and tools in general and knew it was not beyond my capabilities. I'll try to attach a photo of the finished panel and I may be contacted for further information if you or anyone else desires. Best wishes.

P.S. Unable to create a URL for the picture. Contact me and I can e-mail it to you.
JoeC is offline   Reply With Quote
Old 12-03-2018, 06:15 AM   #20
Itasca Owners
Teamfoxy's Avatar
Join Date: May 2018
Location: Sebastian Florida
Posts: 127
I finally crawled under the RV and took a good look at the tanks. GW is only about 6" tall and long and wide. There is only about 1.25" height between the sensors, which are on one end, so clearly they would only be accurate when the MH is perfectly level. Also not a lot of head pressure to push stuff out of the tank.
Our method of control is to operate off the FW tanks and dump GW anytime we fill with FW. (Usually every 3-4 days).
I have noticed that the readings on the tanks vary with whether plugged into shore power or operating off battery power alone. The readings when on battery alone appear to be more accurate.
2005 Itasca Spirit 24V
Sebastian, Florida
Teamfoxy is offline   Reply With Quote


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Who has this air cleaner and what did it cost? FIRE UP General Maintenance and Repair 18 10-27-2012 07:16 PM
What is the best tool and cleaner to remove caulk on roof edges? usaret General Maintenance and Repair 6 05-09-2012 05:00 PM
Ultimate Advantage 40J Air Cleaner Restriction rowesort General Maintenance and Repair 8 09-29-2009 10:41 PM
Cleaner for Eternabond ichn2go General Maintenance and Repair 13 08-18-2008 01:50 PM
Wheel Cleaner suggestions?? smlranger Running Gear, Axles, Brakes, Wheels and Tires 14 05-10-2005 09:00 AM

» Featured Campgrounds

Reviews provided by


This website is not affiliated with or endorsed by Winnebago Industries or any of its affiliates. This is an independent, unofficial site.

All times are GMT -6. The time now is 10:52 AM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.