Gotta say I use the Vermonter's regime, pretty much, and have no problems at all.
Summary.
2005 SD Max (580 gal) with ozonator (which was just replaced, BTW).
Daily only usage (well, mostly daily), and chems aded after that. Weekly done each Saturday; Daily sanitizer: 1 T Cl (Leisure Time 56).
That's it for most days; couldn't be more easy.
Weekly: Follow the Leisure Time regime, for the most part.
2 oz Enzyme to keep the water clear (skipped this one week, and things got cloudy; water is crystal clear usually.)
But NO Bright and Clear (which is recommended), since I've seen here that the SD 880 filter filters out the things that B&C clumps together, and have seen no problems. No scum, etc.
I did do an experiment on eliminating both of these, and that's when the cloudiness appeaed; so tried both to see which did the trick. Tried each of B&C and E to see which fixed it, and E did. (No scum, which is the hallmark of not using B&C.)
Add 7 Oz (shock) tablets. (Correct for 580 gal.)
That's it for weekly.
4 weeks+, dump water/change filter, etc. (This is the plan, especially before winter.... Not done this yet.)
BTW, to reply to the OP, I just got TDS strips from rhtubs, which work well, and I'm up to 1000. Not bad for first fillup and after 6 weeks.
http://www.rhtubs.com/store/test-kits.htmOh yeah, I do use the Taylor chem kit once a week to get precise readings, and LT strips once or twice a week to check. Had to add pH UP (Spa Up) and Ca Up twice in 6 weeks. (Love the Taylor kit; beats strips all hollow! :-) )
But, day-to-day and week-to-week, chem is very stable, much more so that the old Br tub, but that was my first; YMMV.
Also BTW, usage is two people, about an hour at a time, 5-6 times a week.
Comment: I used Br in the last spa, and this Cl regime is a *lot* easier and more stable since there is about 5 ppm just after introducing the chems, and about 0 ppm the next day, as Vermonter and others say. Fantastic. Love getting into 'pure water', as it were.
Any comments from the more experienced users appreciated!
Edit: OT, but I also use 303 on the cover, which keeps it looking like new! I also purchase everything from rhtubs. No relation except satisfied customer. There's no sales tax and no shipping over $60.
Just glad to support a fellow board member!