Calculating shock #'s

May 6, 2009
134
Hamilton, Ontario
Hi Jason and all.

It's been a while since I've messed with the pool because of many medical probs but as Arnold said," I'll be BAAACK"- and I am:).So hopefully on of you ever helpful people can refresh my memory. I just opened my pool and am working to get rid of the cloudiness and I know I need to shock. My CYA is at 60. Dumped in chlorine 2 days ago and the FC is currently at 9.The Chlorine/CYA chart say's CYA 60-Min FC 3 Target FC 4 Shock FC 24.

Now I go to the Pool Calculator and enter NOW as 9 and Target 24 in order to determine how many liters of liq chlorine needed to add for shocking purpose in my pool with 144000 Liters. It tells me 35L to add in order to shock. Am I on the right track? Cheers
 
Assuming you are using 6% bleach (hard to find down here anymore), then you are exactly right.

Make sure you get your pH in the low 7s before you raise the FC up to shock level :goodjob:
 
Now I need to make further adjustments to CYA and TA and my question is : Should the CYA and TA be done in any particular sequence. Today's #'s are:

PH 7.2-7.5 + Good.Lowered from 8.5 w/muriatic acid done yesterday

FC 15.5 and shocking to 24--DONE--added 20L as per Calculator

CYA 40--need to adjust by adding 3K stabilizer--NOT DONE

TA 60.Aiming for 80 .Need to add 5K Baking Soda.
-NOT DONE
 
Shocking your pool is a process... not a one time event. Check out Pool School on "the shock process". You will need to maintain shock levels until you meet all the criteria there.

I would leave your CYA alone until you have finished with the shock process.

You're ph will not measure correctly when you have high levels of chlorine.
 
oletrout said:
Now I need to make further adjustments to CYA and TA and my question is : Should the CYA and TA be done in any particular sequence. Today's #'s are:

PH 7.2-7.5 + Good.Lowered from 8.5 w/muriatic acid done yesterday

FC 15.5 and shocking to 24--DONE--added 20L as per Calculator

CYA 40--need to adjust by adding 3K stabilizer--NOT DONE

TA 60.Aiming for 80 .Need to add 5K Baking Soda.
-NOT DONE
Hold off on the CYA. If you raise it, you will also have to raise the shock level.

I'd wait on the TA as well.

And you probably shouldn't have messed with the pH while you were at shock level - above 10 FC the pH test gets skewed. Concentrate on killing everything, then rebalance when it's done. accurate-ph-test-during-shock-levels-with-r-007-t61076.html
 
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