Black tank - RV-Dreams Community Forum

Mayor · RV-Dreams Community Member

Black tank

Bill Adams · RV-Dreams Family Member

I always dump my black when I am going to dump my grey, UNLESS, you are using a huge amount of grey water or your grey tank just does not hold much. If you use a washing machine or you have several people who like to take long showers, you might want to dump the grey (gray) but not the black. I like to have the black at least 1/2 full and I use lots of water with each (solids) flush. If you use enough water to ensure you have high water to solids ratio then you should be able to dump black at anytime. If you are a dry camping and looking to conserve every ounce of water then you have to ensure that you get plenty of liquid in your tank prior to dumping. Once or twice (or a few times) you might get away without issue but if you do not keep the solid to water ratio high enough you are going to have a problem in the long run.

Mike n Angie · RV-Dreams Community Member

Don't know what unit you have but we happened upon a post on youtube regarding flushing /cleaning black tank. You might want to check it out. We followed this process and were amazed how much waste flushed out after we thought we had the tank clean. I'm certainly not promoting this site, it was just very helpful/useful for us. youtube.... RVGEEKS.com
Good luck.

bjoyce · RV-Dreams Family Member

We only dump the black if it is 3/4 full or more. Our tank monitor shows in 1/4 tank increments, but in our old RV we used 2/3rd since it showed in 1/3rd increments. We can and do dump the grey more often than the black. We have a black tank flush so in cases where we need to dump the black when it is not 3/4 full we back flush it for at least 10 minutes to clean it out. It is best to be in a campsite with sewer (full hookup or FHU) to do the back flush since you are not keeping anyone waiting and not all dump stations have water connections you can use to backflush. We want the grey at least 1/2 full when we dump the black to flush the hose out afterwards. It takes some practice to figure it out but since we have a washing machine we have no trouble filling the grey tank.

Terry and Jo · RV-Dreams Family Member

Larry,

It doesn't hurt to allow your black tank to wait until close to full. As long as you use a fair amount of water to flush each time you "deposit" solids into the tank. As long as the solids are within water, the solids will soften and become less solid.

We are full-timers, but static and not traveling yet. We also have a washer and dryer. I watch the grey water primarily because of the use of the washer. If the grey tank fills first and the black tank isn't, I dump the grey and keep it open when Jo is doing several loads of laundry. When she finishes, I close they grey valve so that water is in the tank to help liquify any food particles that slip down the drain.

I try to watch the black tank indicators and when it gets over 2/3 full, I prepare to make sure the grey tank fills before dumping. Our Mobile Suites has a black tank flush system, so flushing is pretty easy before closing the black tank.

Terry