Reduction of CH

[KurtV]

Your CH is fine. You're at the low end of the recommended range of 200-400 ppm and since you have a vinyl pool, calcium doesn't matter very much (if at all) anyhow.

If you ever do need to reduce it, the only way is to drain some pool water and replace with lower calcium fill water. (I think there are also companies in places like AZ, where the water is extremely hard, that can remove calcium through some process.)