Yes - using tabs will over stabilize (Raise CYA) and raise your ALK and Cal Hypo will raise your Calcium level. The only way to reduce these # is to drain and refill.

Within a year of of getting a pool - I had CYA >200 and continual algae problems. I was skeptical at first about bleach -- but found this forum - I switch to bleach and kept it in control using the adjusted chart for higher Cl. This worked -- but was difficult to maintain the high CL -- I drained and refilled to get the CYA down -- (it's was alot cheaper) -- now I use some bleach at that's about all I have to do.

Bleach is my choice -- but when I can budget the convience - I'll switch to salt.