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mikestock's avatar
mikestock
Explorer
May 06, 2016

Easy and quick extra rinse for black water tank

I know I'm probably not the first to think of this. It is not a complete rinse but it does help insure that all of the particulates get dumped.

If your dump is set up like my Phaeton it works well. I first, try to let my gray water tank fill as much as safely possible before dumping. When I get to the dump station I dump the black tank as usual. Then, leaving the black water valve open, tilt the manifold upright with the hose still attached and open the gray water valve, forcing several gallons of gray water to backflow into the black tank. I then close the gray water valve and tilt the manifold back down, allowing the black water to empty again. From this point you can lift the manifold and let a little more gray water into the black tank before finally closing the black water valve. This leave a little water in the bottom of the black tank if you care to add deodorant. Finally, finish dumping the remaining gray water, as usual.

Just gives me a little more confidence that all of the particulate remnants are allowed get removed.
  • I added a third twist-on valve to the waste outlet. With the grey tank nearly full, I open the third valve and the black tank valve. When the black tank is done draining, I close the third valve and open the grey valve to let it equalize into the black tank as a rinse. Next, I close the grey valve and open the third valve to drain the black tank again, followed by opening the grey valve to rinse the hose. It takes longer to type it than it does to do it.

  • I installed the SaniCon unit on my coach and do this when I drain the tanks. Since the SaniCon acts as a third valve, it allows you to drain one tank into the other.

    What I like about this procedure is that your grey water is typically soapy and is good for lubricating and cleaning the black tank. I usually drain the grey into the black tank three times when I'm doing a good rinse. Each time, floats the debris off the bottom of the black tank.
  • mikestock wrote:
    I know I'm probably not the first to think of this. It is not a complete rinse but it does help insure that all of the particulates get dumped.

    If your dump is set up like my Phaeton it works well. I first, try to let my gray water tank fill as much as safely possible before dumping. When I get to the dump station I dump the black tank as usual. Then, leaving the black water valve open, tilt the manifold upright with the hose still attached and open the gray water valve, forcing several gallons of gray water to backflow into the black tank. I then close the gray water valve and tilt the manifold back down, allowing the black water to empty again. From this point you can lift the manifold and let a little more gray water into the black tank before finally closing the black water valve. This leave a little water in the bottom of the black tank if you care to add deodorant. Finally, finish dumping the remaining gray water, as usual.

    Just gives me a little more confidence that all of the particulate remnants are allowed get removed.


    Sounds like a very reasonable procedure. I have found that with all the soaps that go into the gray tank that it also somewhat "washes" the black tank if only a little bit. A few gallons of "soap-ish" water is probably doing wonders in there.
  • I just use an internal sprinkler device while dumping If no one is waiting behind me I may do a second fill & rinse on the black tank. I also think chemicals is a waste of money. Been doin this for many many years.
  • I have had to use this method a few times to clear a blockage in the black tank drain. Works much better than the robin williams/rv movie method!!
  • Oasisbob wrote:
    I just use an internal sprinkler device while dumping If no one is waiting behind me I may do a second fill & rinse on the black tank. I also think chemicals is a waste of money. Been doin this for many many years.


    I have a sprinkler and use it occasionally, like at the end of a long trip. Some dump stations don't have potable water so an extra hose is necessary. Also, I hate to spend too much time rinsing when others are lined up behind me waiting to dump.

    What I am describing is a quick and easy way to do a little extra cleaning with little time and effort. When practical, I try to hold water in the gray tank from my washing machine to run back through this process, thus adding a little detergent to the cleaning.

    Sounds like Dutch_12078 and DSDP_Don are doing the same thing a little differently. I'm just using what is already there, in my case.