Black/Gray Tank Sensors

[KPMullen]

A recurring theme on here and something I've battled since buying my used DP nearly two years ago... sensors not reading properly. In my case... always reading full even immediately after dumping.
I've read every thread and post, tried every recommended treatment, and bought every recommended gadget over that period.
Two weeks ago, as I prepared to head north from Florida, I purchase two quarts of Thetford AquaMax. The day before departing I dumped both tanks and put 50 gallons of water in each. [75-gallon capacity tanks] I added a quart of AquaMax to each tank. This was basically a quadruple dose according to the directions.
I took a leisurely 6-day trip to New Hampshire with the 50 gallons of hyper-treated water sloshing around in each tank.
I am happy (no, thrilled!!) to report that upon dumping on arrival here the sensors in both tanks are registering perfectly. All green after dumping and then yellow and finally red as they fill up.
The combination of hyper-dosing and sloshing while on the road has done what nothing else has... cleaned the sensors.
I'm now using the recommended 8 oz (in 5 gallons of water to start) in both tanks after each dump. It also serves to control odors.
This is the first product I've tried that actually did/does what it claims and I felt duty-bound to pass along my experience.
Kevin

[Pointerman]

Did the product do it or did 6 days of driving with 50 gallons of clean water do it?

[KPMullen]

I can't imagine water alone would have done it. I have no idea what the previous owners did for maintenance but the tanks had 14 years of sensor fouling to clean. I think it's probably safe to say it was a combination of the two. It needed enough water to keep the higher sensors in the solution in order for the product to work.
Just sharing my experience in the hope someone else can profit from it.
Kevin