Daytime Chlorine loss

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JoanC

JoanC

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May 26, 2012
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Rome, GA
Wondering if someone can tell me if my daytime chlorine loss is typical or if I need to possibly increase CYA to hold it better.

I recently had an ammonia problem which I blasted over a couple of days and went into a SLAM for a few more days. Water looked great and still does.
Successfully passed OCLT several nights but continued to have CC-0.5. This has not changed.
First of the OCLT had FC- 1ppm loss. Others since have been either FC-0.5ppm loss or 0ppm loss overnight.

My problem is my daytime Cl usage. I'm losing 4-5ppm by 5:30 or 6:00 pm. This brings it down to between 1 & 2ppm of FC. At 1ppm or 1.5ppm, it is below minimum.
This requires either 1gal. 1 qut. & 1 cup or 1 gal. 1qut. & 3cups to dose it back up to 6ppm. So to round off, about 1.5 gal. of 10% bleach per day.
I really need the FC to last until about 7:30 in the evening if I can accomplish this.

I've read other posts regarding similar situations and most suggest raising the CYA to hold the chlorine better although if a SLAM were needed at any point it would take more bleach at that time of course.

Numbers as of this evening at 5:30 Note: 7:00 AM FC- 6.0 CC-0.5

FC-1
CC-0.5
Ph- 7.5
TA- 60
CYA- 30
CH- 90
Water temp 86
Air temp - high 90's past several days
pool is in full sun from about 7:30 am till about 5:30.
Evaporation approx. 1/4 inch every other day past week.

I think I included all info.

Thank you for your help!

Joan
 
I am running my CYA at 40 right now and using 2ppm a day. I bring my CL up to 7 each evening. As the month goes on and it gets hotter I will bring my CYA up to 50 and finish out the year at that.

I just wanted to add..

We just started hitting the 90's yesterday. As the water gets warmer you will use more chlorine so I would get that CYA up to 40 and try that for a week or so.
 
Joan, in the South we have been hot and sunny lately. I think you might find 40-50 a little easier to maintain. 4-5 ppm isn't outside the realm of possible normal daily ppm loss, so I bet your water is fine.
 
Thank you everybody! I thought the general opinion would be to bump up my CYA a bit.
I'll take it up to 40 and see if that helps any. I've never been at 50 but may have to go that high.

I'm not worried that anything is lurking in the water because it is still crystal clear and OCLT last night was great with 0 loss. As I said, it is during the day that I lose the chlorine and it gets down to between 1-2 by 5:30 or 6.
I realize this is too low. Each time it has gotten down below 2 (my minimum) I have done another OCLT to be sure all is well. This is happening far too often however and I need to do something to maintain the FC level better.

I'm hoping upping the CYA does it. It may still take as much chlorine but if I end the day with a decent level I'll be satisfied.

Thank you
 
Thank you very much smforte!
I value both yours and Mr. Bruce's experience with your pools a great deal because of your being in my region with like weather.
Your pool is also virtually identical to mine. Uncanny it is!

I added CYA for 40 last evening. Will dose accordingly when I test. I will give the CYA of 40 a trial of a few days and up it to 50 if needed. I'm suspecting that may be, as you have to do it and Mr. Bruce feels 40-50 is going to be it as well.

Thank you all again for your input and help. I thought I posted this last night but must have clicked cancel instead of quick reply in my haste.

Joan
 
Here is the play by play:

I did another OCLT last night. ( To be sure nothing had a chance to grow during hour or two FC was at 1ppm yesterday.)
0 FC loss this am.
7:00 am
FC- 6.5 CC- 0.5 (dosed for goal of 6ppm last evening. Had clouds and rain 6pm till midnight last night. CYA added for goal of 40 last evening, dissolved by this morning.)

5:30 pm
FC- 3 CC-0.5 ( high air temp 98 today mostly sunny.)

Chlorine loss already small amount better. Loss of 3.5 rather 4 to 5 through the day.
I will dose for the Cl target of 7ppm while the CYA of 40 is settling in and see how this works for the next few days. :)

Thank you!
Joan
 
After 4 days of CYA at 40 I'm still losing 4-5ppm chlorine on sunny days. This brings my FC down to minimum or below by 4:30 or 5:00 in the afternoon.

I am able to dose at this time now but in a week or so this won't be possible. I will need to test and dose at 7:30 or 8:00pm.

I will increase the CYA to 50 and hope that will be the magic number. Hopefully it will since it works for smforte who is in a similar climate.

I will report back in a few days to let you know what happens. :)
 

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It's been 5 days since CYA added for increased to 50. Tested third day and right on 50.
Still losing 4+5 ppm during the day. Very hot and sunny. Humid with scattered thunderstorms some days.
Still pass OCLT with 0 loss.

Ask me questions please!!!!

I've never had this problem before. CYA of 30 always worked fine for me prior to this.
I have searched the forum and cannot find any similarity.

Thank you,
Joan
 
When does your pump run? Do you have any water features and if so, when do they run? I'm wondering if you're battling something with the FC that is somehow not exposed to it during the overnight test.
 
JoanC said:
It's been 5 days since CYA added for increased to 50. Tested third day and right on 50.
Still losing 4+5 ppm during the day. Very hot and sunny. Humid with scattered thunderstorms some days.
Still pass OCLT with 0 loss.

Ask me questions please!!!!

I've never had this problem before. CYA of 30 always worked fine for me prior to this.
I have searched the forum and cannot find any similarity.

Thank you,
Joan
Click to expand...

Chlorine varies in strength, what the jug says may not be...I just picked up a case of HASA 12.5% and it is more like 14%, and last year picked up a couple of cases of Walmart 10% that was more like 8%...may be your issue

I might add, are you testing FC, then dosing and then retesting 1/2 hr or hour later after pump has run....or dosing to PoolMath and testing the next day?
 
I kicked mine up to 50 ~ it's been full sun and has gotten hot quick up here in Western, PA. Those conditions were just chewing up the liquid chlorine at 30 and then 40. Still going through quite a bit, but they have been active in the fields, everyone is going crazy with yard work and getting their gardens in & I have a bunch of folks swimming. The water is pristine, I'm just a slave to the jug right now though, so much so I have been checking cc's nightly. I have fresh testing supplies so I am taking the zero reading at face value. Having outpatient surgery this week so hoping I can keep up with the maintenance. If I can't I will have to deputize my daughter ~ eek! ~ but ... I am not going to complain about hot sunny weather, because I never thought it would get here. Now if she breaks my speed stir or we lose our sparkle she'll hear it !
 
I could have and should have answered these to begin with but I'm bad to ramble on so I didn't.
I've just about had it with this!

Thank you both!

Pump runs 24/7
No water features for algae to hide in. I brush religiously several times a week.

As for bleach: Using the Walmart 10% pool bleach. I even check the date to be sure it's the freshest on the shelf.
Strength seems true at 10%. I have tested water then tested again an hour to an hour and a half after dosing and FC was on target.

I usually test every morning near 7 am before sun hits pool. Sometimes I will add a little to get FC to Max of 8 just to try to help it through the day.
This morning the FC was 7 so I didn't add any bleach.

Tested at 6 pm and FC-3. As I said in other post, today was sunny, hot until afternoon thunderstorm then temp dropped. If we hadn't had storm the FC would have dropped even more I think.

I would have tested earlier too. The other days this week have been very hot, high 90's. I've done my 7am test, added a little to get up to max of 8 most days, then test again around 4pm. Certainly no later than 5pm because the Cl has been dropping to minimum and even below some days.

Last year I had CYA of 30, kept the Cl at 2-4ppm due to metal stains with no problem at all.

And by the way, the water is crystal clear and sparkling.
Other numbers are:
CC-0.5
Ph-7.5
TA-60
CH-90
CYA-50



Thank you,
Joan
 
Thanks for letting me know I'm not alone DKT!
I could have almost written your post. Good way to put it, " slave to the jug".

Good luck with your upcoming surgery. I understand your concerns about someone else maintaining the pool while you can't.
I'm having two level cervical fusion in a couple of weeks so I'm in the same boat you are: making sure pool under control so a newbie can handle it for a few weeks.
The bending to pour the bleach in is going to be a problem as well as lifting the jugs.
I can test and husband can put the bleach in BUT he leaves for work at 7 am and doesn't get home till 7:45 - 8:00 pm. He commutes. I'm losing FC during the day and having to add/supplement to stay at or above minimum is my issue.

I've gone "back" to pool school thinking maybe I'm so tired from pain I can't think anymore and am doing something wrong. I've read and even reread posts on minimum and maximum and target chlorine. I will continue to do so and also recheck my CYA with more precision by using measured equal parts of pool water and reagent when we get some sun. It's overcast and cloudy at present.
This is driving me nuts!

Please take care of yourself DKT, before and especially after your surgery!
I'll keep you in my prayers!!
Joan
 
SouthVirginiaPool said:
Joan - did you ever figure out what the issue was for excessive FC loss during the day? Or was that just the way your pool is? Curious new pool owner reading thru daytime chlorine loss.
Click to expand...
Hi @SouthVirginiaPool!
Just saw you post. That was back in 2012 so I really don’t recall. I also had older liner in pool. Whether that made a difference I don’t know but I doubt it.
I’m not having any excess loss at present because it’s not really hot here as yet. We’re actually in blackberry winter with temps of hi in mid 60’s this week. Hi temps and sun Use up chlorine faster than cooler temps and cloudy days. With that being said, I have a large pool (18x41) with a bigger surface area for the sun to affect. Another thing that I try to hunt down is algae hiding somewhere and scrub brush it out. Any amount of algae will use chlorine. Lots of things do. Looking back at my post I can’t say what it was. Sometimes it is as you said, just the way my pool is.
Good luck with yours!
Everyone is here to help you if needed!
Joan
 
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