Russ, take a simple approach to your chemical program, these guys must record the chemical school class every year, and listen to it on their way to work.
If you have ozone, and as you can tell from this thread no one really knows how effective ozone is or how it affects your chemicals. If your water is clear, no bad odors, and feels fresh and clean clean. And you are not getting readings on chlor, then the mix of your ozone and the amount of chlor you are using is working. If the water is not clear, and feels funky, smells funky, it is funky. Just add more chlor, after use.
Also, relating to my first post, unlike most of the programed robots on this board that get off in their den or office at night from using big words on this board. I to have sat in the chemical classes, and public pool and spa certification classes. But I also try to keep things as simple as possible for customers, for spa care. That is one of the biggest concerns that people about owning a pool or spa.
Russ, just add more. When a tub is new the water is untreated, and the bather loads are high. It is not un usual for people to have your problem the first few months.
In a spa, where the water is not exposed to UV rays, which really burns off chlor fast. There is still existing chlor in the water, non chlor shocks don't need much chlor to work off. I am aware, of the difference in bromine and chlorine Chas, but thank you anyway.
I have had good luck with using non chlorine shocks with granular in spas. Much like you use a bromine salt and non chlorine shock. 2 or 3 times a week use a granular after use, and the rest use a non chlorine shock after use. To whoever said, they like to use a tub with low ppm of chlorine, that is why I experimented with this. To keep ppm of chlorine as low as possible. Instead of constantly adding more granular. Even if it is not needed, plus I find non chlor shock make tha water crystal clear and chlor odor down. I have got alot of good feed back from customers that had been using only granular for years in their tubs.