I tested my water this morning:

18000 gallons, gunnite pool/spa combo w/ aggregate finish
FC 1.0
CC 0.0
Ph 7.8
TA 90

I have to assume the CYA is at a good level until my new testing kit arrives.

I added a quart of muriatic acid to knock down the Ph a couple of points and left the pump running. 6 hours later the test result is pretty much the same, a reading of 7.8 with 2 drops of acid demand solution to bring the color into the 7.2-7.4 range. Does muriatic acid take a long time to lower the Ph?