Need to SLAM pool w/SWG but CYA is <30. Should I raise my CYA first?

[Dagobah]

Have been away on vacation for a few weeks. Came back to a pool just starting to turn green. My FC is 0, CYA is <30 (low as my kit goes). Wondering if I need to raise my CYA before shocking with bleach, or if I can adjust after?

Asking, as this chart doesn't list levels for CYA below 60

Levels:
0 FC
7.0 pH
170 tA
<30 CYA

(SWG, 35k gal)

 

[Richard320]

If you're shocking with bleach, you use the chart for a bleach pool.

Once it's all clear and done, then you can jack the CYA level up for your SWG. Low CYA is probably what caused the problem in the first place; the sun got to the chlorine before it could get to the algae, and the SWG couldn't keep up with the demand.

 

[Dagobah]

Ah, I was just looking at the SWG chart. If I use the lower CYA levels from the non-swg chart, looks like I should shoot for 10-12 FC for a shock level.

Agree that my low CYA was likely the cause.