This tidbit discusses how to keep the sludge out of your black tank. This advice comes from a company who came to a talk at a local RV club meeting. I read this on one of the RV forums and thought it had some validity so will pass this along.

The folks at this company say that they use Pine Sol in their RV tanks when they travel... a few ounces each time after they dump... Pine Sol is cheap (sometimes 99 cents in the dollar store) and a bottle will last a long time... they said it does the trick and you can save a lot of money... for short camping trips where you dump more frequently (less than full tank) you have spent a couple of cents, instead of a dollar or two of the other stuff...

People asked about it dissolving "dark matter", and they did not recommend doing that as it forms sludge in the bottom that is sometimes hard to get out when you dump... better to have those little missiles floating on out in the hose they say... and they have cleaned dry sludge from many tanks as it is their business... some people store tanks without a thorough flush (or having that capability) and the sludge dries over time... Keeping a lot of water in the tank is important... As a little input from my own experience, I once time dumped on the way home but forgot to fill the tank with fresh water and chemicals, 2 weeks later it was bone dry and the black valve handle was very, very hard to move. We had to take the whole black tank assebly apart, clean the valve and gaskets and re-assemble it all. For good measure we did the grey tank assembly as well.

Also, they said in all the tanks they have cleaned, toilet paper has not been the problem.. sludge or other buildup... as I have heard before, they suggested some soap in the tank filled with water and then drive over bumpy roads to clean the sensors and sides... Some sensors are on the outside of the tank, but buildup on the sides can still affect the reading... Pine Sol may help prevent that...

Pine Sol is a cheaper solution to more frequent dumps with the short trips.... Someone asked if the Pine Sol would damage the seals... they said it does not unless you used a 50/50 solution over a very long time... they said in 12-15 years of heavy usage you may need to replace your blade valve...

Pine Sol has a very strong smell, so some will be put off by that. I will do some more research and perhaps try it out myself next year.

This article was reproduced with input from RV Stuff N Thingz.