Update...
Really enjoying the spa, thanks everyone for this site and all the good info.
Is a CH of 40 too low?
PH 8 plus, TA 80, CH 40 after first purge, (ahh-some product) drain, fill, drain and fill again.
Aerate over night.
Used 4/5 soft water, and 1/5 hard.
Put in TBSP Alk down so PH...