Everyone who owns an RV should be concerned with maintaining its
wastewater tanks. Problems with wastewater tanks that can be
avoided should be avoided. Wastewater tank repair is expensive.
Due to health concerns, many service facilities will not work on
wastewater tanks and lines until the tanks have been completely
emptied and sanitized. This may be quite difficult when the
tank(s) is in need of repair. So, common sense dictates that the
tanks should be kept relatively clean at all times.
Additionally, improper use of the wastewater tanks can lead to a
build up of solid wastes, which in itself may cause the system
have not been maintaining your tanks I believe you will be
pleasantly surprised the first time you employ these tips. I do
these things and they work.
1. DUMP A FULL TANK
When you are camping and your RV is connected to a sewer/septic
intake, leave the drain valves closed until the tank is full and
ready to dump. Dumping a full tank provides a sufficient
quantity of water to flush solids from the tank. Leaving the
drain valves open allows the water to drain off without flushing
out solid waste. That solid waste will collect in the tank(s)
and cause problems over time.
2. DUMP TANKS IN ORDER FROM DIRTIEST TO CLEANEST
In other words, dump the black (commode) water tank first, then
dump the grey tank. This way you will be flushing out the dirtiest water with
progressively cleaner water.
3. USE WATER SOFTENER
**Calgon Water Softener link**
This stuff is amazing and it works. Buy a couple of boxes of
powdered water softener at the grocery store. You find it
located with or near the laundry detergent products. I prefer
Calgon Water Softener because it dissolves quickly in water.
Cheaper water softeners work just as well but dissolve more
slowly. Dissolve two (2) cups of the water softener in a gallon
of hot water. Then, pour the solution down the drain into the
empty black tank. Use two cups of softener for each wastewater
tank in your RV. The tank's drain valve should be closed otherwise the
softened water will just drain out. Then use the tank(s) normally until it is full and drain it normally. Add a cup of
laundry detergent to the black (commode) water tank at the same
time. This will help clean the tank. The gray water tanks should
already contain soap through normal use.
The water softener makes the solid waste let go from the sides
of the tanks. If you ever taken a shower in softened water you
know that after rinsing the soap from your body your skin will
feel slick. That's because all the soap rinses away with soft
water. Softened water also prevents soap scum from sticking in
the tub. Get the connection? With softened water gunk washes
away instead of sticking. The same thing applies to your RV's
I use one of those clear plastic elbow connectors to attach
my sewer drain line to the wastewater outlet on my RV. It allows
me to see how well things are progressing during a wastewater
dump. This way I can tell if the water softener had
actually done what I had intended for it to do and made solid
waste, which had been stuck to the interior of the tanks, let go
and drain away. I added water softener to all the wastewater
tanks for the next few dumps to be certain all the solid waste
possible had been cleaned away. The wastewater only appeared
black on the initial treatment. I now add water softener to each
tank once after every few dumps to maintain the system.
Occasionally, I pour a gallon of liquid bleach into each tank to
sanitize and disinfect them. I no longer use the blue toilet
chemical because it isn't necessary. I have no odors coming from
my black water tank. Generic brand liquid bleach is cheap and
4. USE A WATER FILTER ON YOUR FRESH WATER INTAKE LINE
Most fresh water contains sediment. Sediment will accumulate in
your wastewater tanks and your fresh water lines. It also tends
to discolor your sinks, tub/shower, and commode. They eventually fill up and
begin restricting the fresh water now resulting in low pressure.
That's how I know it's time to get a new filter. It works, it's
cheap, it avoids problems, do it.
It is recommended that you thoroughly sanitize the water system
upon delivery, following long periods of non-use, and after any
suspected contamination. There are various commercial solutions
approved for RV use available that will assist you in completely
sanitizing the water system.
Prepare a chlorine solution using 1 ½ cup of
household bleach (5% sodium
hypochlorite solution) per 100 gallon tank of water. This solution
can be funneled into an
empty garden hose and forced into the tank by water pressure. Repeat
Complete filling the tank with fresh water.
Open all faucets to release air. Pressurize
the system until the water flows. Turn off the pump.
Allow the solution to stand for three hours.
Drain and flush the tank with potable fresh
To remove excessive chlorine taste and odor
which may remain, prepare a solution of
one quart vinegar to five gallons water and allow solution to
agitate in tank by vehicle
motion (several days if possible).
The same method of installing bleach can be utilized to install the
Drain the tank and again flush with potable fresh water.
SOME OTHER THOUGHTS
I believe occasionally traveling with partially filled
wastewater tanks that contain softened water promotes cleaning
by agitating the water. The same goes for chlorine bleach.
I believe this process works faster and more efficiently during
warm weather. However, I know it works well even during
I believe the process works best the longer the water softener
remains in the tanks. So, I don't add water softener during
periods of heavy wastewater generation. I wait until I know we
won't be generating wastewater quickly so that the softened
water remains in the tanks for several days before dumping.
My tanks are plastic and my pipes are PVC.
Don't be afraid to use your tanks. Just use common sense about
their care and maintenance. These tips are inexpensive to do.
Some ofthem don't cost anything. You have nothing to lose in
trying them and I encourage you to do so. I actually feel a
certain amount of pride in the condition and cleanliness of both
my waste and fresh water systems. Naturally, these tips make
dumping a much more pleasant and sanitary procedure.
If you have odors in any of your water systems these procedures
should eliminate them. Odors indicate a sanitary problem and
degrade the enjoyment you derive from your RV.
When my RV is parked and not in use I place stoppers in my sink
and tub drains. This allows the wastewater tanks to vent through
the vent pipes to the outside instead of through the drains into
Waste Tanks Slope