ASK THE EXPERT: Truck Camper Holding Tank Systems

TCM asks Paul Harris, Lance Camper's General Manager of Customer Service, about how to properly use and maintain truck camper holding tank systems.

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Before joining Lance Campers almost four years ago, Paul Harris owned and operated Paul Harris RV, a Lance Camper dealership in Eugene, Oregon. 


paul-harris-3.jpgAs a previous RV dealership owner, Paul has seen just about everything one can imagine when it comes to RV care and maintenance. 

When we talked Paul about the proper care of truck camper holding tanks, we found ourselves learning a great deal, even after six years of truck camper ownership.  Who knew there was so much to holding tank maintenance and care?  Immediately we knew we had found another expert for our Ask The Expert series.  The following article is the result of our conversations with Paul on truck camper holding tank systems.







ABOVE: Paul Harris, General Manager of Customer Service for Lance Campers


Fresh Water Tank System


In a truck camper, fresh water is primarily used for bathing, cooking, and washing dishes.  When filling your truck camper tank with fresh water, make sure that you use a sanitized fresh water hose.

The sanitized fresh water hose will ensure that your water doesn’t have any residual taste or odor from the hose.  Even with a sanitized fresh water hose, many truck camper owners opt to use bottled water for drinking as the water sources on the road can vary in quality.

Fresh Water fill area
















ABOVE: Every camper fresh water fill features a warning to only use potable water and to sanitize, fush, and drain your fresh tank


When filling your campers fresh water tank, Paul highly recommends connecting your sanitized fresh water hose to a quick fill nozzle with a shut-off valve.  With the quick fill nozzle, it will be easier and quicker to fill your fresh tank as the quick fill nozzle will allow air to enter the tank, speeding up the process.

Once a year you should sanitize your fresh water tanks. To do this, pour a cap full of household liquid bleach into a gallon jug of water and shake it up.  Then pour the bleach and water mixture into your fresh water tank and continue to fill with water until full. Leave it in your tank overnight.  Some folks even drive around with the bleach water in their fresh tank to give the fresh tank a thorough rinsing.

The next day, run all of your sink facets as well as the camper shower and toilet.  You want the water and bleach mixture to run through all of your camper plumbing and valves.  Paul recommends that you flush your fresh water system at least twice with fresh water after this sanitizing method.  Some people also follow this sanitizing method with a baking soda product for taste.


Fresh Water City Inlet
Water Pressure Regulator for a truck camper or RV
If you are staying at a campsite or residence that has an outside water spigot, you can opt to hook up directly to your camper city water inlet.  Once an outside fresh water spigot is connected to the city water connection on your camper, you are using fresh water directly from the spigot, not from your camper’s fresh water tank.

Unfortunately, many campgrounds often have water pressure that is too high for truck camper plumbing systems.  A pressure regulator will ensure that the water pressure does not damage your truck camper plumbing.  When attaching the pressure regulator, it should be attached in the order of faucet, pressure regulator, and then hose.  This also helps to protect the hose.

Once you’re properly connected to a city water connection, turn off your camper water pump and turn on the water source spigot.  This allows the water to run continuously from the camper faucets, shower, and toilet flush just like it does at home.  The water will drain into your grey tank. 


Grey Tank System

The grey tank is where your fresh water drains as you cook, wash dishes, and shower.  There is very little that you need to do to maintain your grey tank.  There are RV grey water deodorizers, but they generally aren’t necessary.  When washing dishes, it is possible that little bits of food can go down the drain and cause odors.  Grey water deodorizers are designed to alleviate these odors if you experience them and keep your tank sensors clean.


Black Water System

Black tanks hold human waste from the toilet in your truck camper.  There are two types of truck camper black tanks; standard black holding tanks and cassette toilet holding tanks.  For detailed information about cassette holding tanks, read, “ASK THE EXPERT: Thetford Cassette Toilet Systems”.  The remainder of this section focuses on standard black tanks as found in the majority of self-contained truck campers.

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ABOVE: The Thetford line of RV toilet tissue and holding tank chemicals

To properly use a black tank system, you need to use a holding tank chemical.  Paul recommends Aqua-Kem (formaldehyde) or Eco Chem (non-formaldehyde) Thetford holding tank chemicals.  These chemicals are designed to control odor, break down human waste and RV toilet tissue, and lubricate the seals on the black tank valve.

During our conversation, Paul stated that you need to decide early on which holding tank chemical type you want to use.  He explained that if you frequently switch holding tank chemical types, the chemicals will not be nearly as effective.  If you have already switched back and forth, Paul recommends resetting your black tank by completely flushing your black tank.  To do this, you dump fresh water down your toilet. 

In a RV holding tank, it is very important that you don’t use regular household toilet tissue.  It does not break down as well as RV toilet tissue and can clog your black tank system.  RV toilet tissue is single ply and will break down quickly in your black holding tank.


RV Exterior Shower and dump valves
















ABOVE: The outside shower (top) and holding tank dump valves (bottom) on a 2011 Lance 992

To properly dump your tanks, Paul recommends the following.  Keep both the grey and black dump valve closed until one or both tanks need to be emptied.  Connect your sewage hose to the dump fitting on your camper.  The other end of the sewage hose goes into the dump station waste tank. 

The next steps need to be done in the following order.  First, open and dump the black tank.  Once it has stopped running, leave the black valve open.  Second, pull the grey tank valve open.  This will flush out the plumbing and sewage hose washing the residual human waste and tissue out into the dump station tank.  When they grey tank has stopped running, don’t forget to close both the black and grey tank valves.  And third, now that you have freshly emptied tanks, it is a good time to pour holding chemical into the toilet/black water tank.


Black Tank flush system on a RV
















ABOVE: A black tank flush connection


Some truck campers come equipped with black tank flush connections.  These connections allow you to flush out your black tank with non-potable water as found at most RV dumps.  To flush your black tank using a black tank flush connection, hook-up a non-potable water hose to the black tank flush connection, turn on the non-potable water, and let the black tank drain into a RV dump station.  This flushing process helps to clean out your entire holding tank and is generally very effective.  Just make sure that you never use your fresh water hose to flush your black tank.

If your camper does not have a black tank flush connection, you can still effectively clean out your black tank using a tool called a toilet wand.  A toilet wand is a long tube that connects to a hose and extends down into your black tank through your toilet.  Once the toilet wand is in the black tank, it shoots water into the black tank to rinse off the sides of the tank and the tank sensors.  Again, do not use your sanitized fresh water hose for this operation.

Some truck camper owners even dump fresh water and ice cubes down their toilets and into their black holding tanks.  Then they drive down the road to clean out their black tanks.  Once the ice cubes melt, the resulting water will safely pass through your camper dump valve.

Paul added that you should never use household toilet cleaners as RV toilets are made from plastic, not porcelain.  He suggested a Thetford product called Aqua-Clean.


Holding Tank Sensors

Holding tank sensors in a RV



















ABOVE: A Lance Camper holding tank with sensors wired and installed

According to Paul, the sensors used on RV holding tanks are not an exact science.  Many things can affect sensor readings including how level your camper is.  For the black tank, human waste and toilet tissue can accumulate on the sensor and give a false reading. 

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ABOVE: We observed holding tanks get installed at Lance Campers last summer

This is why it’s important to regularly clean your black tank with a black tank flush connection or toilet wand. 

If you just dumped your tanks but the black tank is still reading full, it’s time to clean your black tank.  For this cleaning, Thetford has an excellent product called Level Gauge Cleaner.  Other manufacturers produce similar products.

As we’re learning through our Ask The Expert series, there is a short but critical list of truck camper components and systems that need to be cared for and maintained if a camper is to be kept in good working condition.  With this article, we add holding tanks to our list that now includes electrical systems, camper jacks, propane systems, cassette toilets, and camper seals. 

The good news is that camper maintenance does not need to be difficult.  Follow Paul’s expert advice and your fresh, grey, and black tanks will be working for many years to come.  Thank you Paul!


To read more Ask the Expert Articles, visit our Truck Camper Tech section.

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