Ah that makes sense... it puts your fill line below the surface of the water. Mine is above the waterline. I've come to like mine above so I can see it flowing when I am filling so I don't forget am adding water. I presume you don't have an autofill.
Your water is very close to mine just over the hill from you - with the similar high TA fill water my PH is always drifting higher, which happens when I top the pool up during the swim season constantly driving up my TA and thus my PH...I added an acid tank and injection pump to make my PH corrections easier for convenience only.
Back to my very first fill I bumped the CH up to 225-250 and I don't think I haven added any more calcium chloride in 5 swim seasons. I now use my lifetime supply of leftovers in my hot tub when I refill it a few times a year...
With the initial fill water having a CH of 175ppm you will just need to bump it up a tiny amount - after that it will probably rise a tiny amount over time when you top up the pool due to splash out, splash over the safety cover vault wall, and any evaporation. I use our big winter rain storms to help drop the CH if it gets in the high 300's. We received over 48" of rain here last year. If I open my cover during a storm I can use that rain water as a low CH water replacement - this will also drop my Salt and CYA a bit so in the spring I will top those back up to the correct amounts.
Equipment was installed and hooked up this weekend. Flow cell was installed too close to an elbow so they will move it after the salt cell. Cover installation is scheduled for Friday and final city inspection early next week. That means plaster and fill coming up soon.
Looking forward to having water in and scrubbing my walls with my new whale tail brush.