Reading through some of the "stickies" & Pool School articles, I seem to have come across a discrepancy. For a plaster, SWG spa (or pool), is the recommended TA range 130 - 150 ppm or 350 - 450 ppm? Thank you kindly.
Sounds like you've mixed up TA (total alkalinity) and CH (calcium hardness). I think a TA of 130 - 150ppm is a bit high, I target a TA of 70ppm. 350 - 450 is about right for CH, I'm at 350ppm but be careful raising this too much if you've got high CH in your tap water.