We hear it on almost every service call we make. “Does my black tank rinsing system do anything?” Almost every modern RV is equipped with a black holding tank rinsing system. There are two varieties: One that has a static, non-moving nozzle at the top of the tank and another that has a nozzle that spins (which commonly goes by the brand name, “The Tornado”).

Do they work? Yes, most of the time, especially initially. Their purpose is to spray water on the walls of your black holding tank, keeping debris down at the bottom where — hopefully — you have a nice, deep pool of liquid (among other “things”). They do a good job, which is to say that since they are the only tank spraying system you have, using them is better than not.

But a quick look at any RVing message board online that deals with the topic of the tank sprayers will quickly lead you to a number of conclusions: No manufacturer truly explains what the system exactly does, the system seems to stop working at some point, and everyone either ignores the system eventually or considers replacing it.

The foundation of the idea is sound: Spraying water onto the tank sides to rinse off debris and — most especially — toilet paper. The system tends to stop working for two main reasons, the first being that the nozzle often gets covered by the same toilet paper it is intended to rinse off. The other reason the sprayer stops working (or reduces in effectiveness) is that nozzle can get some corrosion on it, reducing the force and amount of water spraying out.

From the various discussions we’ve seen online, people that replace the system says that it initially works fine, but then soon thereafter, they are having problems again with their black tank. What’s the deal here? Well, our theory is that, once again, improper maintenance of the black holding tank is leading the newly installed sprayer system to once again fail — more debris on the nozzle and perhaps corrosion or sediment in the rinse line or spray head.

So what’s the RVer to do? Well, for corrosion and sediment, we recommend that you use some CLR — about a quarter cup — four times a year and let the system flush it through. Just pour the CLR into a water hose supplying your tank sprayer system, connect the hose and turn on the water (to get pressure into the line), let it sit for a half hour and then turn on and off the sprayer system multiple times (letting it rinse for a few seconds). Five minutes of this on-off rinsing cycle should break up any deposits or sediment.

Inside the tank, you can keep the spray nozzle — and the rest of the tank — clean by frequent use of a backflush process. Using the Valterra¬†Flush King on a regular basis is one great way to keep all of your RV’s waste tanks clean and we recommend that every RVer get one and use it at least once a month. The backflushing process will help keep your tanks clear of debris — especially toilet paper in your black tank that can “hang” on your sprayer nozzle or on your tanks sensors.ww

Of course, every RVer should have their waste holding tanks professionally cleaned at least once a year by a service such as Kleen Tank or any of our sister All Pro Water Flow agents. Our use of in-the-tank hydrojetting technology is the only one, true way to get your waste tanks cleaned — from the inside out.