After I dump and flush, I'll add 3-5 gallons of water and chemical. Takes care of what's still in there and ready to go for the next outing. For the last dump of the season it gets thoughly drained and flushed. Then I leave the valves open to dry everything. Freezes hard here and don't want to take a chance on water freezing and maybe cracking the tank. 20 years and so far so good.
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2011 Coachmen North Ridge 290RKD 5'er
2005 Dodge quad cab dually diesel 6'spd manual
1 weird cat with an occasional attitude problem.
Besides adding about a gallon of water, I purchased a Camco external waste gate and on my last overnight stop on a multi overnight trip I fill the black tank up to the 4 light about 3 or 4 times and empty. You won't believe how much paper and stuff still comes out. then I thow in a small bottle of chemical and about a gallon of water, flush, then into storage for about 2 or 3 months never an odor. I forgot to mention after every stop I do a quick flush and add a bottle of chemical
I have found a water meter at Home Depot for $9.98 it fits on the hose.
I use this to flash and parcel fill the black tank. With a definite gallon # I can get a good flush. So far 15 gal of spraying makes a good flush. If I have time I do this twice. This is my tank you will have to check how big your tank is. A clear tube extension from camping world makes sure you are clean.
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