History is 12000 gallon in ground gunite pool
New owner(2 months)pool built 2009
No history of previous owner habits(other than they had pool service)
No previous pool experience
Have some water testing experience
In the last 2 months have had problems controlling ph(keeps climbing) use muriatic acid to control goes down then back up to 8.0 range
Chlorine is 12.5 added as needed(add an average of 70-90 oz a week) 4-5 ppm to 0 by weeks end
Have had since owning white residue at water level on blue tile, diamond shape from grout line
After reading on here got test kit(Taylor)
Found cya was high 100+(off test kit range)
Alkalinity has stayed around 70
Calcium hardness has dropped 270 to 160 originally thought white deposits were from high ph(calcium) but ch keeps dropping
Cya has dropped with adding of pool water due to evaporation(at least I think it has,85-90 test are so subjective to what the dot is you see)
I am lost with ph constantly rising(adding acid to drop) and ch dropping.
Just don't want to chase tail.
Does it seem like I am moving in right direction?
Also there was a nature2 filter that I removed cartridge from after noticing blue pellets in water fall pond area. Cartridge had nothing in it when removed
Sorry for the long winded post
By the way pool water has always been crystal clear and never had algae(for the last 2 months at least)