I keep the galley gray open, plus our washer/dryer combo goes directly out without entering any of the tanks. Every 3 or 4 days I dump the black and bedroom gray. Every week I hook up the black tank flush and run it until it comes out clear. I have been told to dump a bag of ice down the toilet when traveling with an empty black tank and that will get everything off the bottom of the black tank. I may try that next time we move.
Previous: 2008 Montana 3400RL & 2014 3725RL
Current: Full Time in DP pulling Tandem Tow (Kia Sportage/Harley Trike)