Help with my Spring Opening and High CC Levels/low CyA

[cmath011]

Hello,

First I want to say thanks to this community as it helped me maintain a crystal clear pool last year. I just opened the pool on Wednesday and it was a mess of dark green sludge. I measured my numbers with my test kit and the CyA was zero. I realize now I probably should have corrected that before the slam..

The pool is looking much better hour by hour but I am concerned by how high the CC is measuring and whether I should be adding CyA during the SLAM. My test results as of just now are below. I'll bring the FC back up, but what other suggestions do you have about the CC and CyA? Thank you for your help!

FC - 2
CC - 12
TC - 14
pH - 7.8
TA - 60
CyA - 0

 

[mknauss]

Welcome to the forum.
That level of CC is not natural. Unless you have ammonia, and that would mean you would have no FC. So have you added anything other than liquid chlorine?

 

[cmath011]

That's what concerned me, but no, I have not added anything other than Cal Hypo the first day and liquid chlorine since. Any ideas on how to fix it?

 

[cmath011]

Well the numbers this morning did go down quite a bit so perhaps it was just fighting off the absolute bomb of algae I opened the pool to? I'll keep SLAMing, but should I up the CYA now or wait until the SLAM is complete?

FC - 1
CC - 5
TC - 6

 

[V___25]

If you haven't added any CYA, you may want to consider doing that as the sun is going to chew up your FC faster. From the SLAM article:

"SLAMing an outdoor pool is most effective when CYA is around 30 to 40. Below 30 you lose too much chlorine to sunlight. As CYA goes up, SLAMing requires more and more chlorine, which starts to get impractical around 80 or 90. With CYA above 90 we recommend replacing water to get CYA down before you start the SLAM process."

 

[cmath011]

Thank you, the pool is looking much better and the CC has been 0.5 the last two days but as you say, the sun is eating up the FC. I did start adding CYA tonight to buffer it. Thanks for your help.