One year Pool Owner and enjoying every minute of it.

[BigDave]

Great! I want your PB.

[PoolDoc]

. . . membership updated.

I highly, highly recommend that you get a K2006 testkit: http://pool9.net/tk/

This page explains what's happening to your alkalinity, why it's happening, and why it won't stop, unless you can bypass the infinity edge: http://pool9.net/alk-step/ The focus on that page is lowering alkalinity on purpose; you are doing the same, but accidentally.

There is a way to reduce -- not stop -- the loss, but it will require careful attention to your pH, TA & CH with ACCURATE (not pool store!) testing. Damage to your plaster is almost inevitable, if you don't learn this.