black tank question

[tooslow]

We just bought a new trailer. It has a black tank flush feature. With the old trailer, we used to leave some water and bio agent in the tank. With the flush we should be able to get the tank practically pristine. I'm interested in thoughts about whether we need to continue to leave water and bio agent in there.

Thanks!

 

[Rene T]

I still keep a few gallons in the tank just in case there are still some solids in there and also to keep the valve seals lubricated. One thing that really helps when dumping, install a clear 45 Degree elbow at you discharge pipe. This really helps when dumping and flushing to make sure your tank is clean.

 

[Alfa38User]

We use no chemicals in our tank. Simply dump the tank when it is  is 3/4 full or greater, flush using the flush system for 5 minutes or so closing and opening the valve one or twice, close the valve and continue to flush for a minute or two. This will leave a couple of gallons of water in the tank and then turn off the flush.

You definitely need to leave water in there for dilution of the next bunch of "material" and keep the valve seals wet. If you do not, you risk creating the dreaded 'poop pyramid' and plugging up your system. Use lots of water and you will not have a problem, skimp on the water and "you takes your chances".

 

[HappyWanderer]

Not as pristine as you would think. We have the flush system and use a clear elbow, and flush until everything comes out clean. If the camper is going to sit for a while between trips, I'll put lots of water into the black tank after dumping and dump a second time at a rest area near home.

It's surprising how much additional "stuff" gets washed out the second time around.

 

[Rene T]

It's surprising how much additional "stuff" gets washed out the second time around.

And the 3rd and 4th time also. I don't use any chemicals either. Just keep watching the clear elbow for clear stuff.

 

[BruceinFL]

Without any water the knife valve seals will dry and the valve may begin to leak

 

[SubVet]

We use no chemicals in our tank. Simply dump the tank when it is  is 3/4 full or greater, flush using the flush system for 5 minutes or so closing and opening the valve one or twice, close the valve and continue to flush for a minute or two. This will leave a couple of gallons of water in the tank and then turn off the flush.

You definitely need to leave water in there for dilution of the next bunch of "material" and keep the valve seals wet. If you do not, you risk creating the dreaded 'poop pyramid' and plugging up your system. Use lots of water and you will not have a problem, skimp on the water and "you takes your chances".

Poop pyramid!  Never heard that one before and would have spit beverage on the screen had I been drinking. 

 

[blw2]

There is a youtube video of a guy that made up a litle plexiglass tank and simulted waste to test various flush systems
I don't have time at the moment to search for it to link it.... but I'll bet it would be easy to find....

Not completely real world, but it will give you an idea of just how not pristine those tanks will remain.....

 

[Rene T]

Poop pyramid!  Never heard that one before and would have spit beverage on the screen had I been drinking.

You've been a member of this forum for well over a year and you've never heard of a "poop Pyramid".  It seems like at least once every two or three weeks that subject comes up. 

 

[tvman44]

I have a tank flush but always leave a couple of gallons of water in the tank.

 

[Mopar1973Man]

As for storage I leave all knife valves open and allow the tanks to dry.  As for starting a trip I will start with a 5 gallon bucket of water down the toilet of course after closing the knife valves. When I return home I dump my tank in the sewer clean out in the yard. Then fill the tanks again let them stand for overnight. Then dump in the morning. Tanks are spotless no black tank rinse hook up. But then park it under its tree and pull the knife valves open. All sensors always work! No knife valve leaks or problems.

 

[8Muddypaws]

I've called it "The dreaded pyramid of poo" for over 20 years.

A really bad experience with an untreated 10 day fermented black tank convinced me to use chemicals.  We've used 'Happy Camper' for several years.

 

[blw2]

here's the youtube vid I wrote about earlier....... comparing various tank flushers
Agian, not what I would call real world, but interesting I thought
http://youtu.be/dfTd0Slt_cU