adjust cya before or after shocking

[Kateyru]

Yes.

[BigDave]

OK, that could explain how FC went from 16 to 18.5 without adding bleach.
Can you shutdown SWCG without shutting down pump / filter? If yes, please do.
How's the water look, has the cloudy cleared? Running pump / filter 24/7? How's the filter pressure?
Please test FC, CC, and pH add bleach if FC is below 15 and get a FC reading at dusk so we can see how we're doing at dawn.

[Kateyru]

I have shut SWG down. Pump/filter has been running 24/7 except about 2 hours today when I ran robotic pool cleaner. Filter pressure has remained constant since 4/1/12 tho I backwashed late this afternoon. The water is not cloudy and there are no visible signs of dead algae. I brushed and saw nada. I wouldn't say the water is sparkling but definitely is clear. I guess I would describe it as a dull clear. Test numbers at 5pm with sun behind the trees: FC = 15.5, CC = 0 and pH = 7.3 to 7.4. I have not added any bleach today.
So, I should test FC, CC and pH at dawn? I have to leave my house about 6:20 in the morning and will be gone all day. Could you give me recommendations for the morning. I'll test and proceed per your guidance.
Thanks!

[Watermom]

lease test FC, CC, and pH add bleach if FC is below 15 and get a FC reading at dusk so we can see how we're doing at dawn.

Dave, she reports in her post above that her CC was 0 and she had no chlorine loss overnight.

Katey, if tomorrow morning you still show no more than a 1ppm drop and still no CC, then go ahead and let the cl drift down and you can bump up your CYA if you wish.

[Kateyru]

H2O Ma, you're back...so if I have more than a 1 ppm drop or more than .5 CC, I'll need to add bleach, right? Just trying to make sure I'll know how to proceed.

and do I turn SWG back on in the morning?

[Watermom]

Yes, If more than a 1ppm drop or CC greater than 0.5ppm, then you're not done and you'll need to add bleach. Otherwise, let the cl drift down. Keep your SWCG off until your cl drifts down. No reason to waste your cell life.

[Kateyru]

got it, thanks!

[BigDave]

If you have no more than 1 ppm FC loss overnight (with the SWCG off), your CC is at or near 0 and the water looks clear; you can let FC drift down. The complicating factor here is that we lost no FC last night but the SWCG was on so... we lost as much FC as the SWCG produced overnight.
If your FC is 14.5 or higher in the morning then we're done with the algae battle and you can let the FC drift down.
If you can't watch it tomorrow and your FC in the morning is 14.5 or below, add some bleach to get above 15 and turn on your SWCG. Run another FC / CC test when you get home and let's take it from there.