Gray Water tank lights on monitor not working

The GEO Method works on black and grey tanks. I use the cheapest detergent and water softener I can find. I usually use the powdered softener in powder form and dissolve it first

Next time you travel fill the grey tank about half full with clear water and some strong detergent.

X2 on the Geo Method.
But, tank sensors are not known for their accuracy. Some work, many are not very accurate.
The best thing is to learn to know when the tanks need dumped, don't rely on the lights.

Mine aren't working either, same as probably 75% of all other RVs are not working either. Yes, you can try all sorts of stuff that mite clean them, but it will be short lived. I would say that most RV'ers have better things to do, and just learn to live w/o monitoring holding tank levels,.....which. given a little learning time, is really very easy to do.

You can first try a qrt of lemon cleaner found at any grocery store.

If that doesn't work Thetford makes a real good gray tank sensor cleaner.

It states right in the manuals that certain minerals in well water can foul the sensors. This cleaner addresses the mineral issue.

http://www.amazon.com/Thetford-24545-Level-Gauge-Cleaner/dp/B0006H93FA

When I bought my first used RV I cleaned the tanks with the sensor cleaner and then thereafter a quart of lemon cleaner goes in the gray tank after each dump. And I do NOT allow any foodstuffs or grease go down the RV kitchen sink.

My Sensors work 100% all the time.

Quote:
And I do NOT allow any foodstuffs or grease go down the RV kitchen sink.
My Sensors work 100% all the time.
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Well, that would probably work, but then I wouldn't need any cleaner either !
Grease is why they quit working. 75%, (probably more than that) of RV'ers let some grease.......and food particles go to the holding tank. That's what holding tanks are for.

My gray water tank sensors will periodically act up as to be expected because of the accumulation of grease, toothpaste and other nasty stuff. My solution is to remove the small drain plug on the bottom of the tank and insert my homemade flusher, which is attached to a garden hose, and aim the stream of water at the sensors located at the corner of the tank. Takes about 5 minutes total and it works every time!