Keeping RV gray and black tank level sensors clean

Wayne

Administrator
Staff member
I have hear many stories of black and gray tank sensors getting gunk built up on them and giving false level readings.

From my understanding there are two main types of tank level sensors. One is a strip that's stuck on the outside of the tank, like the SeeLevel from Garnet and works by sensing when there is a change in what's around the sensor. The other type I'm familiar with is the small probes that test for continuity. The liquid in the tank will allow a small amount of power to flow between the probes, indicating the level. We have only ever owned the SeeLevel gauges.

There are several products you can buy to help remove the gunk that gets built up on the walls of the tanks and internal sensors. The external sensor strips are so sensitive that you can place an object near the sensor and it will make the gauge read full. A small amount of build-up on the inside of the tank can do the same. One of the products is from Thetford and looks like this:
Level-Gauge.jpg


We do not use a commercial product, but do use our own concoction that has worked very well over the years.

A dishwasher tablet and a teaspoon of surfactant, like Lemi-shine:
LS.jpg


I put these two cleaners in every time I empty and rinse the gray and black tanks, even when we are sitting. The surfactant keeps solids and liquids from sticking to each other. I don't know how much they really do to keep the tanks clean when sitting, but it sure doesn't hurt anything.

The key to keeping the inside of the tanks clean as a whistle is to use the cleaners while you are moving. When we move, we drain and thoroughly rinse the tanks until only clear water comes out. Then, fill the tanks with clean water about 1/4 full, add the concoction, and start driving. When you get to your destination, drain and rinse the tanks as soon after you arrive as you can, when the gunk will still be suspended. You won't believe how much gunk the cleaners will clean from the inside of the tanks.

I have found that the surfactant is as important if not more important than the detergent. We have used this method for most of our RVing career and have found it keeps our tanks fresh and new on the inside. Well, free of build-up anyway. :)

What do you do to keep the build-up off the inside of your tanks?
 
This is something I need to get better with. I've been all over the map the last year, usually because the tanks are last on my list of things to mess with. I usually will have something in them when we're traveling, at least some water and a TST packet (Or a grey tank tablet), but I really need to standardize on something and stick with it. I'd think powdered laundry detergent might be a decent choice as well, but we use the little dry sheets these days and I'm sure those probably wouldn't be good since they appear to be made out of starch and would probably leave slime in the tank.
 
We have also found that if you keep the film/gunk build-up from inside the tanks, they don't stink. We use nothing else in the tanks to keep the smell down, as we find it's not necessary.
 
I've been having trouble with the tank sensors not reading correctly. Will give it a try but can't every trip, state parks usually don't have sewer hook-up.
 
I've been having trouble with the tank sensors not reading correctly. Will give it a try but can't every trip, state parks usually don't have sewer hook-up.

That's partially where my habit comes from. As nice as our state parks are, most of them are water/electric only.

I should use some of the freshwater I keep in the tank to put some back in the tanks before I leave, but usually there's someone waiting behind us and I don't want to hold them up, and by the time I get back in the truck I can't be bothered with stopping again. So I don't put water back in them until we're home, and that doesn't help with agitating the water around.

I guess I need to be less lazy.
 
I just never worry about black tank levels. I won't ever fill mine up. I could see being on the road full time with it being a concern.

I have camped at a coe campsite without sewer, and the line at the dumpstation was long. I skipped and camped again the next weekend and dumped the tanks with out issue.
 
I just never worry about black tank levels. I won't ever fill mine up.
Yeah, I won't fill mine either, not going to take a chance to get a large toilet paper teepee. I've seen the results and the remediation doesn't look like much fun.
 
Yeah, I won't fill mine either, not going to take a chance to get a large toilet paper teepee. I've seen the results and the remediation doesn't look like much fun.
I never let my tanks go dry, after i empty the tank , i put a couple of gallons of water back in with a splash of dish soap. That low level of water, going down the road seems to keep the tanks fairly clean.

I've never had a black tank problem. My trailer has a rinse hose connection, i've never used it. My previous trailers never had any rinse hose connection.

Keep some water in them and soap or a surfactant like you mentioned, and you won't have a problem. AS long as you always use plenty of water when flushing toilet paper!! Fill up the bowl with water when you flush toilet paper.
 
When we stay at campgrounds without sewer hook ups we dump and go at the dump station then when we get home we hook the rinse line up to the black tank and always get more out. Going to give Wayne's procedure a try.
 
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