I full timed in my RV for three years then had a lapse of sanity and moved to Denver. I’m back full-timing as of the first of August.
I want to share with you a tip I picked up from the forums and some experimentation with my own combination of treatment methods for the nasty ol black/grey water tanks. They can be tough to clean and keep smelling a fresh as a daisy and that can be a particular problem if your tank(s) have not been maintained. Everything I mention here I also do to my grey water tank and the best part is it’s so much more earth friendly than most, note I said most RV tank treatments.
I got my RV used and the previous owners had NOT maintained the tanks well at all. In fact, the whole coach was pretty dank overall, but that was to my benefit as I negotiated the price down because of it. Anyway, the tanks were full of sludge and some dankness that I really don’t even like thinking about but the result was a pretty nappy smell made worse when moving. I tried those Venturi vents, all kinds of chemical tank treatments, flushing for hours, etc… Nothing worked… I don’t give it a second thought since I made this discovery. Boraxo and Arm & Hammer Laundry detergent!
I put 1/2 cup of Boraxo (the laundry ‘water softener’ product, I prefer the powder) and 1/4 cup of Arm & Hammer laundry detergent in the tank every time I dump it and I have not one issue with any malodorous smells since I finally got the tank clean. BUT it takes some time to fully work. Let me see if, in delicate terms, I can explain why.
Your tank, especially in an older RV, will end up with a layer of scum and particulate matter. It builds up in the corners and will continue to build up over time till it can be a 1/2″ or more of gunk on the walls of the tank. It is very hard to remove and who wants to put there hands in there anyway! Some biological tank treatments will eventually clear some of this out but that stuff costs too much.
If you parked for long periods of time or never move your RV it may take a little longer but if your moving around you can really accelerate the process. The next time you head out on a road trip, dump the tanks and fill them about 1/4 full. Add 1 cup of boraxo and 1/2 cup of detergent and head down the road. The rocking and shaking action of the road will mix up the tank and essentially speed the softening and eventual flushing out the tank. When you get to your destination, as soon as practical dump and flush your tank. You will be amazed at how much nastiness will come out.
For me it took 4 – 600 mile days on a cross country trip from Idaho to Virginia to get things working good, but once I got that accumulated junk out my tanks are much fresher and it costs about 25% of the cost of the RV tank treatments you can buy.