Tuesday, July 5, 2022


Are you managing your RV tanks? Part 2

By Jim Twamley

Properly managing your RV’s tanks can make your life much happier. Last week we talked about fresh water and black water tanks. Let’s talk about those other tanks this week.

Gray water tanks

After I’ve drained the black tank and have closed the black tank valve I open the gray water tank valves. It’s very important to close the black tank valve before opening the gray water valves to avoid odor entering through the sink drains and vents. Opening the gray water valves will wash out any remaining toilet paper and waste left in the sewer hose.

We can usually go one or two weeks this way until we have to take a trip to the dump station to empty our black tanks. Gray water tanks fill much faster than the black tank. When two people take showers and do dishes, the tanks fill up fast and need to be emptied more often. You can empty the gray water into a portable dump tank. I normally reduce the amount of gray water dumping by showering in the local shower facility if available.

Hot water tank


Not much to manage here except to clean it out once or twice a year. You open the drain plug and either hose it out with a strong stream of water or blow it out with high pressure air. This helps clean out the mineral buildup. You can also buy a cleaning tool that fits on the end of a garden hose. This allows for blasting a pressured stream of water into the tank. Some models have anode rods that must be replaced. Be sure to refer to your user manual for details for your model.

Propane tanks

I have a 5th wheel, so I use two 30-pound propane tanks. Make sure your tanks are secure for travel. They are not designed to lay on their sides, and aren’t safe to do so. For safety purposes some people turn them off when traveling – I leave mine on. I also have a spare tank that comes in handy.


I purchased a plastic base to hold my spare tank upright in my storage compartment. Here’s a base, found on Amazon.com. I have two cylinders hooked up to the system, and one spare. I have also used this spare tank for the BBQ. With a spare, you can leave one tank hooked up while you fill the two empties.

Fuel tanks

I carry two plastic 5-gallon fuel containers. One is for diesel, the other for gas for my portable generator. On diesel engines, it is important to keep your fuel filters clean and try not to run your tank all the way to empty. Otherwise you may suck up some sludge into your fuel system, like I did somewhere in Indiana one summer. Suck sludge and you’ll have a problem on your hands. I have had to use my extra diesel fuel on more than one occasion – you’ll be glad you have it!



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David Schmidt
1 year ago

I have recently bought a 2006 a frame camper it only has a black tank. No gray tank. Camper has shower toilet and a dual. Kitchen sink. Is this typical to have a just a black tank or
On a towable camper?

1 year ago

Why are the gray tank outlets not 3 inch like the black? Sure would make for a much faster dump.  

Richard Hubert
1 year ago

Re: Black Tank Maintenance – Most dump stations have a faucet and hose nearby to help use the black tank rinse fitting (if your RV has one). I will use if available, but some just have a faucet with no hose, so what I do is fill my 5 gal. bucket and pour that down the toilet to help flush out the tank of debris stuck on the insides. Sometimes I will do this 2 – 3 times as with a clear connector on our drain hose we can see how dirty/clean the sewage flowing out is.

1 year ago

If you carry a spare propane tank in a storage compartment, the bottom of the storage compartment has to be vented (propane is heavier than air). In addition the compartment must have no openings into any other storage or living areas. Failing to do this is a recipe for disaster.

Ronald W. Kreusel
1 year ago

Fuel Tanks – you mentioned keeping a 5 gal container of Diesel. I’m wondering where do you keep that? We travel in a Class C/Class B+ type – not sure where I would store any fuel containers.

John Koenig
1 year ago

I use a slightly different technique when emptying my tanks. Both my grey and black tank have a 55 gal capacity and, I generally have nearly full tanks when I dump. After connecting my sewer hose, I BRIEFLY open the grey valve and allow just enough grey water to fill the hose. This takes 5~10 seconds. During this time, I visually check for leaks and, the soapy grey water wets and “lubricates” the hose. Should there ever be a leak, I’d be dealing with grey water, NOT black water. Having established that there are no leaks, the grey valve is closed and, I SLOWLY open the black valve and allow the black tank to drain completely. Black valve gets closed, grey valve gets opened and, once that tank is empty, the grey valve is closed and I finish up storing the sewer hose. The extra step of opening the grey valve BRIEFLY adds less than 30 seconds to the job but, provides added peace of mind that I WON’T have a black water leak. I did not originate this system but, can’t remember who told me.

1 year ago

If you’re pulling a 5th wheel with a diesel pickup with just the factory tank, you’re very limited by that small fuel supply, so yes, a spare can of diesel is essential. Far better – do what I did after running out of fuel in the middle of West Texas. Some helpful soul had purloined 5 gallons from my tank that I didn’t miss until too late! So after adding a locking gas cap to the truck, we stopped in Chico CA on our next trip South and had the good folks at Transfer Flow Inc. install a 50 gal aux tank in the bed of the truck. Having 80 gallons on hand rather than 30 makes ALL the difference in your fueling program. Try it, Chuck. You’ll LIKE it! We sure did…

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