You will need to do a partial drain/refill to lower the CYA level at some point but as to whether you do that now or wait until spring is up to you. If you don't do it now, then you should keep your FC level higher to prevent algae growth. The usual rule for an SWCG pool is an FC that is around 5% of the CYA level so around 6 ppm as your target. With the water getting cooler, algae will grow slower anyway, but then chlorine will kill the algae more slowly as well.
As for the CH, the calcite saturation index with your numbers before you added the acid is around +0.3 which isn't too bad for causing scaling in a manually-dosed plaster pool, but it would likely have you get a lot of scaling in your SWCG cell. However, as the water gets colder, your SWCG will probably shut off and you'll be manually dosing the pool over the winter. So whether you do the partial drain/refill now or later is up to you. If it were my pool, I'd probably do it now just to avoid any scaling issues if I got lax over the winter and the pH went up too much, but that's just me.
Bookmarks