I've found Thetford's
Campa Potti XT works best for us. The 5-gallon holding tank means we don't have to find a dumping facility as often. But of course it has to fit into the space available.
I believe it's Thetford's budget model as it doesn't have a gauge. We've had models with a gauge in the past but found we were emptying before the gauge was even registering.
To reduce the overall weight of the potti for moving it around (and to avoid freeze damage), we don't use the upper tank. We have a few water bottles with sports tops and find they do a better job of washdown (because you can aim them). But the trick is to have the just-right place to store them so they're both convenient and won't spill.
We do a couple of things to stretch out the time between dump stations. If other facilities are available, they take priority. We also try to use the potti for urination only but it's certainly not an inviolable rule.... especially at night with bigfootses and skunk apes hiding in the bushes just over there.
I also like to have disinfecting towelettes available and use them to clean both the upper and lower portions of the potti after emptying and washing out the holding tank. And in hot weather, I occasionally do a quick washdown and disinfection of the bowl.
Emptying the holding tank and cleaning up the potti aren't pleasant tasks. But once I got my procedure down and gained some experience with various designs of dump facilities, it became a routine, easy job.
Also-- one of the things in dealing with dump stations is the sewer-pipe cap. Many are designed with a foot-pedal with the assumption that you'll step on that pedal just long enough to insert a sewer hose and then the cap will rest on the hose. But a porta-potti doesn't have a hose and the spout doesn't work well with the cap in the way. Often, you'll see a rock nearby and it can be used to keep the cap open. You'll also typically see a locking flange on the cap. I've sometimes hooked a bungy-cord hook on that locking flange hole so my wife can hold open the cap while I work.
I'll also mention a potential problem with the potti slide-valve. Slides sometimes dry out and become more difficult to work. I had one I couldn't open at all after long storage. It came loose after soaking for a bit but since then I've occasionally lubricated the slide. Thetford sells a lubricant for this but also says olive oil will work. I just put a couple of drops of olive oil on when the slide seems to need it.
Here's a photo of the setup we have in the van....
(click to enlarge)
(That combination's a bit too big for the Hawk so we store its Campa Potti and bottles in two different places)
I would really like a gauge or something besides me sloshing it to see how full. We pull camp most nights and have access to unload but not always the case. I searched this post because I'm looking to replace my Camco that I purchased day I brought Hawk home in 2015. Open to recommendations... wish I'd got a model with the cartridge potty.
