For the last month or two, I've had a feeling that my ozone bubbles weren't performing as they did when I first bought my Sovereign last summer. I checked the ozone lines for water or acid buildup, but they were clear. While performing my second water change yesterday, I stuck the Shop-Vac hose down over the filter standpipes for no particular reason other than to suck as much old water out of the tub as possible. After refilling, I noticed I had more ozone bubbles than I can ever remember. Maybe there was buildup in the injector that got sucked out by the vacuum cleaner. I've never had any water quality issues even while the bubbles were greatly diminished, but I fear the consequences should the ozone be unable to be sucked into the injector - just seems like the ozone would build up in high concentrations in the generator.
The only other "problem" I've experienced was near the end of my second fill when I got a couple of flow errors and one high limit trip. I found the cause when I loosened the circulation filter - LOTS of air bubbled up from it. Apparently, it had been sucking air bubbles from the turbulent water in the filter compartment and trapping them inside the filter. Letting the air out of the filter and resetting the hot tub would temporarily cure the problem. I always maintain my water level and never experience excessive foaming, so maybe the filter was just clogged and I didn't realize it. We'll see how it performs now that I'm on my third fill and filter cleaning.