RV Black/Gray Tanks

A word to the wise, when traveling… dump your tanks (black and gray) and then put about 5 gallons of clean water back into them. Add to that water one cup of detergent (I use liquid Oxy-Clean…others use Dawn…or..?) and drive to your next destination. The sloshing of the soapy water will loosen and remove and residual stuff that may be hanging around inside your tanks. At the destination, dump your tanks and put fresh water back in them and use as you normally would. Repeat this procedure every time you travel. If the toilet is sealed as designed, odors will not penetrate into the rv and as an added benefit, your tank sensor will work as designed.

Another source of odors in the rv may be due to a faulty Air Admittance Valve (AAV) that is located on your sink drains (sometimes on the shower drain too). This small device can get stuck open and then allow gray tank odors to escape into the rv. They are easily replaced if needed.

rockhillmanor wroteTried them all and this is what I found to be even better than Happy Camper. And IMHO the ‘only’ one that actually works. And it worked even in the incredible heat of a Florida summer where I had no hookups and full black tank between dumping.

Note the words ‘powerful odor control’ on the label. There are two different types of this holding tank chems on the same shelf by the same company. The one that states on the label.
“powerful odor control” and “breaks down waste” is the ONE to buy.


As far as your gray tank no need to use black tank treatment. Just pour a quart of any lemon cleaner into tank every other dump or so.