Please confirm need to shock

[sandycreek91]

I think I need to shock my pool, but am looking for someone else's opinion (besides my own) to confirm.

We got a rain storm through the other night. The next morning, my pH had moved from 7.4-7.5 to almost 7.8. Then, the water started getting cloudy, and has slowly started getting a greenish tint.

Test results:
FC: 6
CC: 0
pH: 7.5 - 7.8, closer to 7.8
CYA 40
OCLT: -2

I know, I know .... OCLT of -2 and green water should be a no brainer to shock. What I can't figure out is the CC of 0. Why is the CC test registering no combined chlorine if there's obviously green in the water? The CC has not moved from 0 since the rain storm.

Am I right to shock the pool? And if so, what's up with the CC test?

 

[AnnaK]

If I had water with a green tinge I'd pour in a jug of bleach regardless of the CC test results. If OFCL means overnight chlorine loss and you lost 2 ppm, that's a clue that something isn't right.

 

[sandycreek91]

If OFCL means overnight chlorine loss ...

Oops -- not sure what my brain was typing. I corrected that.

 

[JasonLion]

No question, definitely shock. CC can stay at zero the entire time you have algae often enough. CC at zero doesn't really tell you anything.

 

[sandycreek91]

Okay, loading up the wagon with bleach.

Thanks, Jason!