Holding chlorine overnight

Probably a dumb question but I have been advised to keep the chlorine at shock level until it holds overnight. Does that mean to the exact number?

Last night when I went to bed I brought the chlorine to 12ppm (cya of 20 or less...added stabilizer a few days ago) This morning at 9:00 my chlorine was 10.5. It also rained last night. All numbers as of this morning....

FC 10.5
CC 0
PH 7.2
TA 80
CH 140 (working on raising to 200...concrete/guinite pool)
CYA waiting to test

The water is clear...not "sparkling" clear...especially in the deep end but it is clear and a pretty bluish color. Do I need to keep the level at 12ppm throughout the day today and again tonight or can I let it drop to the appropriate number per Best Guess chart?

Thanks!
Andrea

In normal operation my pool uses 2 ppm of chlorine daily.

You have no CC, so I'd say you're good to go letting it drop to the appropriate number on Ben's BG chart :)

Quote:

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Originally Posted by AndieP

Probably a dumb question but I have been advised to keep the chlorine at shock level until it holds overnight. Does that mean to the exact number?

Last night when I went to bed I brought the chlorine to 12ppm (cya of 20 or less...added stabilizer a few days ago) This morning at 9:00 my chlorine was 10.5. It also rained last night. All numbers as of this morning....

FC 10.5
CC 0
PH 7.2
TA 80
CH 140 (working on raising to 200...concrete/guinite pool)
CYA waiting to test

The water is clear...not "sparkling" clear...especially in the deep end but it is clear and a pretty bluish color. Do I need to keep the level at 12ppm throughout the day today and again tonight or can I let it drop to the appropriate number per Best Guess chart?

Thanks!
Andrea

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That's a pretty small drift. That plus your CC=0 would tell me it's time to let it drop off.

How much? Need to know your CYA. When did you add it and how?

C.

What has worked well for me in the past is to hold my Cl level at shock value until I was satisfied with the clarity of the water. If your pool consumes additional Cl during this period, you are still clearing. If it does not, there is no harm.

Running pump 24/7 and backwashing as needed is essential to this clearing process.

I added the CYA last Friday. I added it through the skimmer so I haven't backwashed yet. I did give in to the urge to test it before the week is up....and it was only a slight bit clouded at the very top of the tube. The pump has been running 24/7. My kids plus the neighbors kids are begging to swim today...8 kids total....which means I will probably be shocking tonight anyway.

I was thinking of adding some DE to the filter to see if that would help get the water just a bit clearer.

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Originally Posted by duraleigh

What has worked well for me in the past is to hold my Cl level at shock value until I was satisfied with the clarity of the water. If your pool consumes additional Cl during this period, you are still clearing. If it does not, there is no harm.

Running pump 24/7 and backwashing as needed is essential to this clearing process.

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But his CC=0. Wouldn't that indicate he's not consuming any? Further reduction would be more attributable to the sun, no? My attitude is the less chems, the better. In this case, I think I'd be looking for the filter to do it's job at this point.

C.

Quote:

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Originally Posted by ChuckD

But his CC=0. Wouldn't that indicate he's not consuming any? Further reduction would be more attributable to the sun, no? My attitude is the less chems, the better. In this case, I think I'd be looking for the filter to do it's job at this point.

C.

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I think the original post said that it dropped overnight.:)

But it could have dropped due to the rain?

Quote:

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Originally Posted by Simmons99

I think the original post said that it dropped overnight.:)

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Maybe he lives above the Arctic Circle!
I know, I know.... ; )

He reports a point and a half drop over night. Chlorine's volatile. That's how I attribute what's really an insignificant drop when you also consider all the variables in the testing process.

C.

Ok...I am a "she" not a "he" :D

Thanks for the information....I was just thinking that a drop from 12 to 10.5 was minimal and wondering if that was considered "holding overnight."

It did rain last night and it was 9:00 by the time I tested this morning so the sun was already up.

Andrea

I feel your pain (and apologize!):

Our three and a half year old recently took it upon herself to trim anywhere from 1 to 6 inches off her beautiful brown hair depending on where you looked at it. Now that it's been cleaned up by a hairstylist freind, we think she looks like a candidate to be a nun, others meet us in restaurants and stores and comment 'what a cute little boy' or my favorite, 'Hey little buddy!'. She just smiles.

I think your water's pretty clean (clean enough for my kid!). Like they say here, if you have a sand filter (you don't say) add a cup or so of DE. If you have a DE, use a skimmer sock. IMO that, and POP, is what'll finish clearing it.

C.