CH level in fiberglass pool with SWG

[BobN54]

My pool's un-adjusted CH is 90. I am aware recommended ranges are 250-650 (TFP a,b,c's), 350 to 550 recommended | 250 to 650 acceptable (TFP Pool Math), 200-400 recommended | 150-1000 acceptable (APSP and NSPF). I go by the TFP recommendations for all the other chemical levels, however I'm trying to understand what benefit raising the CH will have to my gelcoat fiberglass pool, PVC pipes, sand filter, SWG, or the other chemical levels? I've done the reading on CH, and I don't get it, at least in the case of a fiberglass pool. Bringing the CH to the TFP number requires adding 10+ lbs of Calcium Chloride. That's a lot of snow-melter in the pool, and I'm hesitant.

CH = 90
TA = 90
CYA = 55
ph = 7.6
FC = 3.5
CC = 0.5

 

[Texas Splash]

The main reason is really for stain prevention since today's FG pools should not have any calcium added during fabrication. Plus, statistics from across the TFP population showed that 250 was a reasonable minimum number for all to achieve. Still, some FG owners chose not to increase it to 250, and if you chose to err on the side of caution and not add enough calcium to make it to 250, that's certainly your call.

On an unrelated note, with summer in full swing, if your pool gets full NC sun, you may want to increase the CYA a bit to 70 and make sure the FC doesn't dip any lower. Hope that helps.