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Sometimes, my RV experiments turn out exactly as I had planned; and sometimes I’m surprised.  This experiment turned out to be a case of the latter.  See what I mean in this video:

So here’s the deal.  Stef and I have years of experience with a regular RV toilet and black tank.  And we’ve got two years under our belts now with a composting toilet.  But we had never used a cassette toilet in our RV.  In fact, we were downright dismissive of them given our experience with a composting toilet.  “There’s no way they could have enough capacity for us,” was our main objection.  But again, we were making that judgement without having used one, so I decided to change that.

I swapped out the toilet in our RV for a Thetford Curve.  While not a true European “through the wall” cassette with wheels, the principles were basically the same.  The curve has a 5.5 gallon waste water reservoir.  That’s about the biggest we could find.  When full, it would weigh over 40 pounds, so that’s really the practical limit for the cassette option.  I reasoned that would give us the best possible case for cassette capacity.

We took off on Friday afternoon for a biking and hiking weekend in southern Utah.  We both completed a century bike ride through Parowan, UT, and then did some camping and hiking in the forest to the east of town.  I’m happy to report we had a fantastic time, and the cassette toilet was a great partner throughout, silently doing its job without complaint.

In fact, most of the benefits we sought with a composting toilet also apply to the cassette.

  • Won’t freeze
  • Doesn’t fill your black tank
  • Doesn’t drain your fresh water tank
  • Easy to install


But besides just those, there are many other areas where the cassette toilet beats the composting toilet easily.  We go over more of these in the video.  Suffice to say that in most respects, the cassette toilet compares favorably to the composting toilet.

But then we got home and realized that when you put the entire experience into perspective, it looks something more or less like this.


And this WAS WITH THE CHEMICALS ADDED TO THE WASTE TANK EXACTLY AS PER THE MANUFACTURER’S INSTRUCTIONS.  This is what we added – it’s what the manufacturer shipped with the toilet.

So while the cassette toilet wins in every other way we can think of, it lost six hundred and forty billion points when it came to emptying.  We’re sorry, cassette toilet.  That experience alone … that ONE TIME emptying a cassette toilet was enough to kill the dream for us.  We won’t be trying that again.

So, we’re back where we started, with a composting toilet in our RV, Lance.  I have a couple ideas on how to make this work even better, and I’ll be trying those out in the months ahead.