I agree. I've got my tub for 5 months now and I'm using Aquafinesse. The tub had been in store for 4 or 5 months and I never quessed that the pipes were dirty. First 2 months the water was bad after a month. Green and kind of thick, if you know what I mean. I bought the Aquafinesse spa clean treatment and cleaned my tub. When I send water through the hole where the filter is, I saw cloudy water coming into my tub. So I cleaned it there with a bucket of hot water as well.
After that it was a walk in the park. I discovered (mainly because of this forum) that I used the tub too much for just 1 treatment a week. So I moved up to adding Aquafinesse every 5 days and cleaning the filter after 1-2 weeks, switching it with another one. Every day I check the chloride tablet and if it is nearly finished I add the next one.
Last month I bought a new parasol, the type you slide under the spa. I felt bad that I had to empty and refill to get it in place, because the water was still sparkling. But I'm confindent if you have a clean tub and maintain correctly, you can use the water way longer than a month.
Good luck!