Cleaning grey water sensors

If you know the sensors are the problem and want to get the job done without messing around pick up some powdered borax and dump some down about 1 pound and get water in tank to a level about 1/2 full. And take on a drive for about a day. This is not for maintenance that you should do to keep them clean. This is to really get years of build up off them, think of scrubbing something with a high ph level. You might want to try other stuff first but if you've given up and about ready to replace sensors try some borax. Not "boraxo" the soap or laundry product that contains borax but borax. I can usually find it at a bait store for curing salmon egg roe or skeins (what ever you want to call them). Be careful in pure form pretty potent stuff. here found article about how it cleans http://chemistry.about.com/od/howthingsworkfaqs/a/howboraxworks.htm
(Be prepared for many to say your nuts) again not for maintenance but when you need to get them in shape to be able to get on maintenance. schedule for your tanks. Info comes from a full timer in our park that passed away maybe 20 years ago and full timed probably 30 years before that in a old beat up "fireball" trailer pulled by his really old, old International pick up. One could only guess how many it had on it.