I’m pretty sure Scripps water by itself tends to have LOW PH and Alk, rather tHan high..
So, the extremely high ALK would be from something else you are dosing in manually — DONT ADD ANY MORE! Doing a water change WITHOUT adding in any PH/Alk additives should lower the Alk
This...... no buffers no nothing. Alk titration is the most inaccurate btw. so double check.
also test for ammonia. also smell the tank, to rule out rotten egg smell, that's bad. .