We bought our first camper a few weeks ago and this will be our second trip. When we bought it the black sensor said it was 2/3 full, on our first trip we emptied it and flushed it with a Flush King, sensor still says 1/3 full. I have been lurking on here and read about putting ice in the black tank, going for a drive, then dumping, but cant remember how much to use? Also use Dawn, yeah? How much? Any other tricks to get the sensor to work?ThanksJessica

I know this won't answer your question. I don't know how much ice to use. But, those tank indicators never work. I think most everyone learns how to cope without them. When I first started traveling with a fifth wheel in 1996 I did everything to get the tank readouts to work. It was a losing battle. After a while you will learn to gage how full the black and gray water tanks are by the usage. And, some fresh water tanks, like ours, are made of that tupperware plastic so that you can see water level.

~~~ Sh EEEttt ~~~ that's what it is ! ~~~Get use to Black water tank monitor (NEVER READING EMPTY or CORRECTLY)....The ICE TRICK they say a bag or two. Many will say save your money or ice! Just chilling the black water.The sensors evidently are REAL sensative. We have tried all the tricks, with back-flushing for like 45 minutes, a dozen times re-filling and still does not read empty.....We do use some soap and deodorizers, just to keep down smells.Have found to COMPLETELY FILL tank before heading over to dump, a full tank will help with higher water-pressure pulling out "ITEMS".No biggie after a while you can gauge without the sensor when truely filled.......Markiemark

Dump a bottle of the cheapest Walmart fabric softener in the tank and go camping. Leave it in till the next time you would normally dump. The more miles the better. Works for us on our C Do it once or twice a year.

A good winding road (snake) with several ups and downs does wonders. I use a 10 pound bag about every other month, "just because".. Does it work??? Makes me happy so it's what I do.

I would say save your money with the ice. Think about the size of your tank. It has to be 30-50 gallon and now think how much ice you got to put into it for it to slosh around, not to mention how rough or curvey the road has to be to get that ice to slosh around. Not to mention that most of it get melted before you are 2 miles down the road. In most cases if it did clean a sensor it would have gotten cleaned with just filling with water and dumping again. But as has been said you may as well learn to deal with it cause they will never work. If your toilet burps it is full. My gray tanks don't work and they have no solids in them. Face it, most RV manufactors are using cheap chinese junk.

how much ice in black tank to clean sensor? | Good Sam Community

21 Replies

wintersun
Explorer II
May 25, 2013
I have had zero success with ice and 100% success with a sprayer on a rod that is sold for this purpose. But its impact is momentary. The next time we drive with anything in the tank the sensor is again worthless.

If it is important to have an exact reading the only real solution is one of the two types of external sensor kits that are not affected by the contents of the tank.
mlts22
Explorer II
May 24, 2013
I've seen some people cut an access port (using a screw cap) so they can hand-clean the black and grey tanks with a mop and a wet/dry vac. This can even be useful on freshwater tanks since one could dump ice in there, not for cleaning it out, but for cold water on a hot Texas day.
Luminajd
Explorer
May 24, 2013
Wow, guys. What a variety of answers! Thanks for all the info.
Garry_Gayle
Explorer
May 23, 2013
I use just good ole Oxyclean, all my sensors work and the Cameo is a 2004, never wasted ice in the tank thats for the JD
mark5w
Explorer
May 23, 2013
Check out this web site for another way to clean black and gray tanks: https://sites.google.com/site/cbruni/

Know quite a few RVers that use that method with excellent results.:)
RCMAN46
Explorer
May 23, 2013
I use the cheapest automatic liquid dish washer soap I can buy. I use about a cup after every time I empty the black tank. At the end of the season two bags of ice on the way home from last trip of the season.
DanoT
Explorer
May 23, 2013
I turn the water pump off so there is no water pressure, then "flush" the toilet so the valve opens but no water flow. I then shine as flashlight into the tank to see the sewage level.
skipnchar
Explorer
May 23, 2013
Ice in the black tank is a VERY poor way to clean anything. Use some black tank treatment and it will be as clean as it gets.
sndman7
Explorer
May 23, 2013
Here is what I do to keep our sensors working.

About every third dump I put about a gallon of Pine Sol in the tank, use the black tank flush to fill the tank. Let it sit for a few hours, dump and flush with a clean tank of water.
Also when checking your tanks press and hold the switch for 15 to 20 seconds and see if indicator lights go out.
Works for me, every time.
Clay_L
Explorer
May 23, 2013
The problem is not the sensors being dirty but is due to the tank walls being gunked up and fooling the sensors.

Even the non-contact sensors on the outside of the tank can be fooled if the walls are cruddy enough. SeeLevel even points this out on their web site.

The SeeLevel web site says "If sludge buildup in the tank becomes extreme the gauge will cease to operate (the tank will always read empty), so by monitoring the signal level the tank can be cleaned before the buildup gets excessive".
From HERE

Anything you do to help keep the tank walls clean may help.
Flushing, adding some detergent and water before you drive for a day or so might help.

I have the TrueLevel non-contact system that Winnebago went standard with in 2005 and right now my black tank reads full when empty. The gray tanks shows 2/3 full when empty.

Over the ten years we have been full timing I have tried everything people say will work and nothing worked.
If I pressure wash the inside of the black tank (have done that twice), the level will be measured normally for a few months and then start to lie.

I think the problem is worse for full timers and that may be why some weekend or short term campers find that detergent or some other method works for them.

I just dump it every ten days and don't worry about it anymore.