well, thank you all for your input. I think that the answer is that my filter is kaput. The water is just getting nastier- in fact, no way am I using the tub till I drain, refill, replace the filter and start over. My dealer did not give me any guidance as to water care except to read the LT info in the start up kit, which is why I used clarifier, and I missed the small print in the Arctic manual that says not to use clarifiers with micropure filters. After that I was told that moderate clarifier use should not be a problem (therfore the additional small doses), but that seems untrue.
My dealer has not been much help in any of this, but I have been getting quick responses from the tech services dept at Arctic, and the consensus seems to be bad filter. I cant decide if I should ask that I be given a new filter free of charge, since it was obviously my error that lead to the problem, but lack of guidance that lead to my error (and I was supplied with chems contraindicated for my filter :-/).
This is just a hurdle, and a learning experience, but I'm going to write to Arctic customer service (even though some of my opinions have already been passed on) and politely suggest that they educate and train their dealers fully BEFORE releasing them to represent their product. (This comment stems from not just the filter issue but other small isses as well.) It is frustrating to me to love this spa so much and yet feel like choosing it meant sacrificing good dealer help, and I think Arctic can improve upon this, at least in my neighborhood.
On the bright side: If this is the correct diagnosis, then with a new filter, I should be ready to go. I'd prefer for excessively hard water NOT to have been be the issue here, even if I do have to buy a new filter. Now just have to find the time to get the thing and do a water change!
