adjust cya before or after shocking

[aylad]

I'd backwash even if the pressure hasn't risen to get rid of the stuff that's been filtered out.

Keep in mind that a dirty filter will filter better than a clean one--if the pool has been clear since the last backwash, there's really no reason to waste the water if your pressure isn't up...

Janet

[BigDave]

My concern here is that pool may have come down from shock a little early, we had 0.5 ppm CC yesterday and 1 ppm FC loss overnight. I'm thinking that the stuff in the filter is contributing to that 1 ppm FC loss.

[Kateyru]

Sunday 7 am test results were FC = 7 and CC = 0. I haven't backwashed today. If/when we are ready to increase the CYA--yes, I want to get to 70 - 80--I have dichlor and stabilizer/cya so can go either way. Before you suggested the dichlor, I was planning to use CYA. Dichlor has not been on my radar previously. Plus CYA seems more efficient based on the ratios you gave.
So, should I backwash first? then test cya, pH and TA at the same time then increase the cya then the TA then the pH???????

[BigDave]

FC was 7 this morning as well as yesterday morning? Is the SWCG on? The pool covered? Did you add chlorine? Was it really cloudy yesterday?
If your FC is holding overnight and you have no CC then ignore my suggestion about backwashing early - no need at all.
The dichlor adds both FC and CYA, If you're willing to manually dose the dichlor for a few days to keep your FC in range(SWCG off), you'll save a little of your cell life, get closer to your CYA goal and use up your supply of dichlor.
- or - if manually adding the dichlor sounds like a pain, turn on the SWCG, put some stabilizer in a sock(start with half of what you think you'll need) and hang it in front of a return.
Either way test FC an pH daily add Borax if pH drops. Keep FC above the minimum on Ben's Best Guess Chart. Remember: As you approach your CYA goal, your minimum FC will go from 3 to 5.
Give it a week before you test your CYA - no need to waste the reagent. The granular stabillizer disolves very slowly and you'll only be adding a portion of your CYA goal with each dose if you choose dichlor.
I wouldn't worry about the TA, 80 seems pretty good, lower TA helps reduce pH rise cause by SWCG use. If you find your pH too unstable, look around these forums for establishing a Borate buffer.
Let us know what you decide and how it's going.

[Kateyru]

FC was 7 this morning as well as yesterday morning? Is the SWCG on? The pool covered? Did you add chlorine? Was it really cloudy yesterday?
If your FC is holding overnight and you have no CC then ignore my suggestion about backwashing early - no need at all.
The dichlor adds both FC and CYA, If you're willing to manually dose the dichlor for a few days to keep your FC in range(SWCG off), you'll save a little of your cell life, get closer to your CYA goal and use up your supply of dichlor.
- or - if manually adding the dichlor sounds like a pain, turn on the SWCG, put some stabilizer in a sock(start with half of what you think you'll need) and hang it in front of a return.
Either way test FC an pH daily add Borax if pH drops. Keep FC above the minimum on Ben's Best Guess Chart. Remember: As you approach your CYA goal, your minimum FC will go from 3 to 5.
Give it a week before you test your CYA - no need to waste the reagent. The granular stabillizer disolves very slowly and you'll only be adding a portion of your CYA goal with each dose if you choose dichlor.
I wouldn't worry about the TA, 80 seems pretty good, lower TA helps reduce pH rise cause by SWCG use. If you find your pH too unstable, look around these forums for establishing a Borate buffer.
Let us know what you decide and how it's going.

[Kateyru]

Yes, FC = 7 yesterday morning and this morning. SWG is still off. Pool is not covered. I did not add chlorine but did add some salt. Yes, it was very cloudy yesterday (the explanation for unchanged FC of course).

Using dichlor is fine. The CYA (per K2006 test kit) is 30. It's going to take alot of dichlor, to go up 40ppm, isn't it?

CONFESSION: the TA = 80 may not be accurate as I have not tested it with K2006 kit. (Don't ask.) Do I need to test it now?

Do I need to keep filter/pump running 24/7 as I work with the CYA?

"Let you know how it's going" makes me laugh. You can't get rid of me this easily or quickly.
I LOVE my pool. Thanks for helping me become better at maintaining it.

[BigDave]

I'm sorry if that sounded dissmissive - not intentional.
As far as the pump, it depends. Are you planning to dose the dichlor into the skimmer and let it dissolve on top of the sand? How often and for how long do you run it on timer? Could you divide the run time into two or three periods a day?
When you have a chance run the FC CC pH and TA so we can see where we are.
Use up the dichlor you have on hand to maintain FC. When it's gone, put on the SWCG, wait a few days and test CYA then figure the plan to bring your CYA up to desired level using Granular CYA.