Sorry for the long post, but I hope this helps someone else searching for what I couldn't find or helps me in case there is a disaster.
Tinkering around trying to fix a no heat problem, I broke off the output from my Freshwater III Ozonator. The repairman came and replaced the recirc pump to get it hot again, but said those output valves are not replaceable in the old style (came with my Jetsetter in 2010), so I would need a whole new unit for $300-400. So, he unplugged it and I'm back to tinkering. The recirc now makes an annoying bubbling sound (which goes away if I cap the O3 hose) and from the posts I did find here, I really want that running.
The output hose had become very brittle and coated with white gunk, I guess nitric acid; it was also nearly opaque yellow. I followed the cleaning instructions and ran a cup of vinegar through it which didn't seem to do much. My first thought was to jam the hose onto what was left of the output nozzle (basically just the threaded part), so to soften it up, I soaked the end in boiled water. Unlike the vinegar, the hot water was dissolving the white gunk, so I massaged some out and soon realized the hose no longer had negative pressure. I guess the gunk got swept up and stuck somewhere causing a blockage. Reminded me to work on lowering my cholesterol. I couldn't blow it out, so I dragged the whole thing out to clean, and surprise, the brittle hose snapped in a place where it was deformed from being stuck between a pipe and a wall. Figuring the gunk was all stuck in the side closer to the ozonator, I used a spare 1/4" hose as a jumper that fits around the hose and the threaded output nozzle. Probably not very well because I am still getting bubbling. Is that normal when the ozonator is off? I haven't tried to power it up yet since the repairman really cranked the circuit board cover closed and I started to strip the screw. While I'm waiting to deal with that, happy to take any input. Considering getting some hose clamps if it appears close to workable.