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A couple weeks ago, I was pondering the following question:

Does the decreased flow rate from a maceration-type pump (as opposed to a standard 3 inch hose) cause problems with suspended materials in the black tank “settling”?

Yes.  I actually wondered this.

Upon having a thought like this, most people would chalk it up to that too-big burrito they had at lunch and just let it go.

Not me.  I had to know.  So I came up with an experiment, but the first thing I would need to complete the experiment was a clear black tank.  They don’t make them in clear because, well, ick, nobody really wants a clear black tank.  So I was on my own.

I have absolutely zero experience in plastics fabrication.  Most people would see this as a road block; but I chose to view it as an opportunity to learn new things, make 7 trips to Home Depot, and drive all over town looking for Weld-On #16 acrylic solvent.  (This, according to the internet, is absolutely necessary for such a project).

With my $150 worth of supplies* in hand, my task for this weekend was to build the “Black Tank Simulator”.

*Yeah, I know. But let’s just pretend I didn’t spend $150 on a project so that we can see inside an RV poop tank

Building the Black Tank Simulator

The simulator is just a clear, watertight tank with an open top.  At the bottom, there is a 3” ABS pipe fitting, which leads out about a foot, and terminates into a twist-on 3 inch Valterra blade valve.  With the right tools and the right glue (the internet was right about that Weld-On #16) it actually wasn’t too hard to build.  That solvent was also good for bonding the ABS sewage pipe to the clear acrylic.

But would it hold water?


In spite of my amateur solvent-welding skills, yes!  It holds water.

And will it dump properly?


Yes!  Apparently so.

So we’re calling this effort a success.  Next, I have to develop a standard (and tactful) tank “mixture”, and find a product to test.  I think I’m going to start with “The Sewer Solution”.    So stay tuned for black tank experiments from the Fit RV Labs!

Also on the agenda for this weekend was re-shooting our RV Video Tour.  The sun was out, and the weather mild, so we called for a favor from our friend Kyle, who acted as our camera man for a day.  We got about half done with all the footage, so that’s another video I’ve got coming up.


Hope your first weekend of Spring was as productive as mine!