Waste Tank-Management Tips — Back to Basics

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December 1, 2017

rv holding tanks

rv holding tanksRV holding tanks — some management basics.

Here are some waste tank management tips for those who may be relatively new to RVing or to extended campground stays. This will deal strictly with using the standard 3-inch gravity hose. The optional macerator type Sani-Con will be covered in a separate post at a later date.

Upon arrival at your campsite, presuming the waste tanks are empty, hook up the sewer hose and open the gray water gate valve. This generally can be identified by a label or observing the smaller feed pipe behind the slide valve. This valve will be left in the open position.

As time passes you will notice that your tank monitor located in the coach will indicate zero change to the gray level while the black tank level increases daily.

When the monitor shows the black tank has reached about ¾ full, go out and close the gray tank valve. With the normal use of the household water, the gray tank level will rise shortly. When there is about a quarter of a tank or so, you can now empty the waste tanks with the following procedure.

  • Open the Black tank valve
  • When the black is empty, flush the tank (If so equipped)
  • Close the black valve
  • Open the gray and leave it open
  • Repeat the same process when the black tank fills again over time

In time, the tank’s level sensors may become affected by grease or food waste in the gray, and solid and paper waste in the black. This may result in inaccurate tank level readings.

The following tips may prove beneficial in correcting this issue.

  • Pour a little dish detergent down the sink drain and fill the gray with water to about half of its capacity. Travel with this to agitate and dump at the next stop.
  • Fill the black tank via the toilet to about half of its capacity. Just before hitting the road, dump two party bags of ice cubes into the toilet. Hit the road. The ice cubes will scour the tank walls and hopefully the sensors will once again be unimpeded.

So, remember that the black tank is always dumped first and then closed prior to dumping the gray. Additionally, you should pour a little water in the sink and shower drains after layups or after travelling. Full drain traps will prevent odor from the gray water tank. This routine will keep your RV holding tanks in good shape.

Well, that’s just some basics.  Hope it is of help to some. Find all the accessories you need at Camping World.

Peter Mercer – With a Black and Gray Tale

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  1. Peter Mercer

    Yes, great point! In fact I made that comment on a post that is being published shortly on tips for Sani-Con users. And yes, you are right about it being much easier to deal with should a spill occur, Thank you for reminding us on this tip.

  2. Anonymous

    While I like your info here, I learned from a column somewhere that, when you are ready to dump your tanks, open the gray first just to make sure there are no leaks and then close it. If a calamity does happen (like your drain hose comes off like it did for me), it will only be gray water and not black. After you have determined that all is well, drain your black, rinse, and then follow with your remaining gray water.