New to managing my pool: Question - CC breakdown in to FC?

[jnorin]

After opening the pool a bit early this year, it has been settling in to good balance and clarity as I have taken over the routine maintenance after the pool service did the opening last week. I will be adjusting levels over time to hit the TFP recommended levels for plaster/SWG. Logs available.

I've been letting the SWG do its thing, and as a science project, calibrating the FC ppm of impact it has over time, to drive the FC levels up to break down the residual CC. That seemed to have hit the trigger in the past day, as the FC shot up from 5.6 to 11.2 and the CC went from 0.4 to 0.1. Is the FC rise related to the CC drop expected? The SWG should have only added 2.2 ppm before any natural daily loss. pH also rose unexpectedly from 7.4 to 7.8. It did rain ~1" between readings, and the salt level drop matched the % volume increase perfectly.

I have turned down the SWG and will start letting the FC drift back to the target range, while I am purposefully bringing CYA up to 70 from 0 at pool opening in steps (now at ~50). I will start raising CH once the material arrives. I plan to lower TA over time as pH creeps up, but don't want to fight the pH/TA circle with chemicals unnecessarily. No easy aeration options in our setup until it warms up and swimmers do their thing

Thanks for any comments and/or recommendations!
John

 

[mknauss]

UV from the sun shining on the pool surface is the primary method to remove CC. FC breaking down ammonia based organics creates CC.

 

[Rancho Cost-a-Lotta]

Have you tested the CH of your fill water? You may want to keep your CH where it's at now. It will continue to rise with evaporation and top-offs.

 

[jnorin]

CH 260. Not sure I follow why it would rise with an overall constant volume (and should drop with rain and backwash/drain).

 

[Oly]

Summer evaporation is significant and refill with high CH ppm tap water is required. This will raise your CH but back washing and rainfall will slow it some.