Another way to help clean the sensors is to drive between locations with about 1/3 full tanks with some sort of cleaning product added. In my previous Suites with the regular in-tank sensors, using bleach some times or Dawn some times or Cascade sometimes almost always resulted in good readings for some time, only to re-occur at a later time.
No longer a problem with the SeeLevel gauges in the '15 Suites.
2016 Tiffin 40 QBH
2015 38RSSA, traded
2005 TK3 #1869, 10 yrs of memories,
2017 F450 KR--one more Ford is it
2009 F450 4x4-died; 2010 F450-retired