@RandyC have stories to tell about Vertex CaRX design and leaks lol.
It does in fact have the possibility of leaking (as is the case with anything though). There are three high-risk leak points, all of which ended up leaking on me.
1. Connection between CO2 diffusion chamber and sicce input connection can leak if not screwed in properly because of debris or a pinched o-ring. Teflon tape can help allelivate the problem, but make sure it's clean and you align it carefully when attaching.
2. Union that connects sicce output with main chamber is plastic welded. Don't over tighten the union or you'll break the plastic weld that holds the pvc pipe to main chamber. Absolutely do not pick up the unit by the sicce pump or diffusion chamber, even when empty or you could break the weld. I had to use DevCon Plastic Welder and silicon to reattach and seal to ensure it wasn't leaking anymore.
3. Push connect adapter in secondary chamber is a slip fitting and is barley glued in. An accidental pull of ro tubing or twist of the secondary chamber while in the notched base plate can lead to the slip fitting getting pulled out. I added some teflon tape and glued it down with DevCon Plastic Welder.
I just got the unit used about 7-8 weeks ago and after fixing everything, the unit has been leak tight for a month now. So, if you get this unit, it works, but take caution with handling it.
And actually if you're interested, I could consider parting with my nicely fixed unit mostly because the footprint is larger than I thought. I have it installed remotely in my pantry and my wife isn't so happy how much space it takes up.