Cloudy pool

deenamccauley

LifeTime Supporter
May 29, 2007
177
Alberta, Canada
We have a very heavily used pool and it has been cloudy for a week or so. My numbers have been good up until the last 3 days and have been getting progressivley worse despite my shocking the pool the last two nights.
I had a CC of .6 so shocked with granular (56%) 1800 grams on Monday (needed the increase the CYA anyways) Yesterday the CC was down to .3 but by night back up to .6. Shocked with 8 liters 12% liquid chlorine last night to bring the levels up to 15ppm.
This morning my numbers are:
FC 6.4
CC .6
PH 7.1
CYA 25ish
Alk 110

Do I keep shocking? Am I not bringing up the levels enough?
 

frustratedpoolmom

TFP Expert
LifeTime Supporter
In The Industry
May 20, 2007
12,179
SWSuburban Chicago, IL
With that much of an overnight drop yes, keep shocking until the FC holds overnight.
You should probably get your CYA up between 30-40 so if you have any more Dichlor you can use it.
For a CYA of 30 shock level is 12, just keep testing and adding hourly to hold it there.
 

deenamccauley

LifeTime Supporter
May 29, 2007
177
Alberta, Canada
frustratedpoolmom said:
With that much of an overnight drop yes, keep shocking until the FC holds overnight.
You should probably get your CYA up between 30-40 so if you have any more Dichlor you can use it.
For a CYA of 30 shock level is 12, just keep testing and adding hourly to hold it there.

Thanks....i should add that I have an automatic feeding so what level should I be keeping it at during the day?
I still have swimmers.
 

deenamccauley

LifeTime Supporter
May 29, 2007
177
Alberta, Canada
deenamccauley said:
frustratedpoolmom said:
With that much of an overnight drop yes, keep shocking until the FC holds overnight.
You should probably get your CYA up between 30-40 so if you have any more Dichlor you can use it.
For a CYA of 30 shock level is 12, just keep testing and adding hourly to hold it there.

Thanks....i should add that I have an automatic feeding so what level should I be keeping it at during the day?
I still have swimmers.

Sorry....you have answered that. 12ppm. I should really give myself a chance to absorb an answer before I ask a question.
Thanks again
 

deenamccauley

LifeTime Supporter
May 29, 2007
177
Alberta, Canada
Update:
I've had the chlorine levels above 12 now for over 48 hours. Yesterday my CC was at 0 for the bulk of the day.
Last night reading
FC 13.4
CC 0
Ph 7.2
CYA 25ish
Alk 110

Then this morning:
FC 12.2
CC .6
PH 7.1
Alk 110

So if I am still getting combined chlorine do I still need to keep the levels that high. I didn't get that big of a drop in actual FC reading so I'm not sure why my CC was so high.
Thanks
 

Steve456

LifeTime Supporter
Jun 3, 2008
132
Texas
With an overnight drop of 1.2 ppm FC and a CC of .6 I say that you still have algae and that you need to continue shocking.

You do not state how you test the water. Given the difficulty of the CYA test I would shock the pool at 14 ppm FC and hold the FC at 14 until an overnight test shows less than a .5 FC loss and no CC. It appears to me that you still have algae. Unless you hit the algae hard enough the algae will continue to grow and you are just wasting time and money by not adding sufficient chlorine.
 

deenamccauley

LifeTime Supporter
May 29, 2007
177
Alberta, Canada
Steve456 said:
With an overnight drop of 1.2 ppm FC and a CC of .6 I say that you still have algae and that you need to continue shocking.

You do not state how you test the water. Given the difficulty of the CYA test I would shock the pool at 14 ppm FC and hold the FC at 14 until an overnight test shows less than a .5 FC loss and no CC. It appears to me that you still have algae. Unless you hit the algae hard enough the algae will continue to grow and you are just wasting time and money by not adding sufficient chlorine.

I test with a Taylor DPD FAS CK 2006
I just tested CYA again and it is 30ish. I always find that a difficult one to test and because I just added CYA and Dhiclor on Wednesday I know that isn't really what it it will end up at.
The health inspector was out today and although I continuely tell him that some things just take time and patience, he really wanted me to do something so I did add some MPS.
I am getting my levels up to 14 and will hold them there until things clear up.
Is there anything else I should be doing?
Thanks for the help.
 

Steve456

LifeTime Supporter
Jun 3, 2008
132
Texas
From your posts I assume you are maintaining a community pool.

Most members do not recommend MPS for outdoor pools. It is an unnecessary expense. See how-does-mps-work-as-a-shock-t18181.html

Even after you have killed all the algae the pool may remain cloudy from the dead algae. It has taken my pool one week of running the pump 24/7 to return the water crystal clear. I prefer to shock with bleach to dichlor. When you are shocking you must maintain the FC at 14 until the overnight test shows no organics. Then maintain the FC at normal levels and run the filter pump.

A pool store would tell you to add a clarifier, vacuum the pool, and refill the water. You might save a day or two. I recommend that you let the filter do its work and remember from now on to keep your FC up.
 

deenamccauley

LifeTime Supporter
May 29, 2007
177
Alberta, Canada
Steve456 said:
From your posts I assume you are maintaining a community pool.

Most members do not recommend MPS for outdoor pools. It is an unnecessary expense. See how-does-mps-work-as-a-shock-t18181.html

Even after you have killed all the algae the pool may remain cloudy from the dead algae. It has taken my pool one week of running the pump 24/7 to return the water crystal clear. I prefer to shock with bleach to dichlor. When you are shocking you must maintain the FC at 14 until the overnight test shows no organics. Then maintain the FC at normal levels and run the filter pump.

A pool store would tell you to add a clarifier, vacuum the pool, and refill the water. You might save a day or two. I recommend that you let the filter do its work and remember from now on to keep your FC up.

Not a community pool per se....we own a campground and it has a pool. So it's very busy. I do not routinely use MPS but adding it allowed me to do something for the health inspector who has little understanding of pools. Personally though, I do find that MPS helps at times.
My filter runs 24/7 from the day we open to the day we close and the pool always has chlorine in it as I have an automatic feeder for both 12% chlorine and muratic acid.

I think the biggest problem for me is that we never close the pool during the day so I cannot just got out and add chlorine every hour, I have to rely on my feeder which does not always have the capability to keep up.
I've had the pool now at 14ppm plus since Wednesday.
Last night FC was at 16.2 CC 0
This morning it was 14.2 CC.2
PH 7.2 Alk 100 CYA 35ish

So I'm still seeing a drop in FC so i will continue to keep it at shock levels for another day and see what happens.
 

chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
12,082
San Rafael, CA USA
Since it sounds like the pool has high bather load, it could use some supplemental oxidation. That's why you find that the MPS seems to help since it can oxidize some bather waste faster than chlorine, though it's about 3 times as expensive (for equivalent amount it can oxidize). Usually in a residential pool that has lower bather load, chlorine and sunlight alone are enough to keep up and have minimal Combined Chlorine (CC). If your pool isn't in full sun, then that can slow down some of the oxidation of bather waste.

The more usual options for commercial/public or other high bather load pools are to use UV or ozone to supplement in a more automated way than manually adding MPS. This is especially important for indoor high bather load pools since they have the worst combination with no sunlight and generally poor air circulation. Enzymes are another option (something like Orenda CV-700, ORB-3 Pool Enzymes Plus, K4Products Eco Pool Enzymes Plus, Pool Enzyme 5100, etc.) as these help oxygen oxidize urea and other bather waste usually cutting down on chlorine demand and disinfection by-products.

You can also try to enforce having people not pee in the pool. Ben Powell has said that when he enforced a rule of everyone getting out of the pool for 5 minutes every hour, that the chlorine demand and CC issues went way down, probably because people would use the bathrooms instead of the pool. Of course, that may not be practical in your situation (for a humorous look, see this video).

Richard
 

deenamccauley

LifeTime Supporter
May 29, 2007
177
Alberta, Canada
chem geek said:
Since it sounds like the pool has high bather load, it could use some supplemental oxidation. That's why you find that the MPS seems to help since it can oxidize some bather waste faster than chlorine, though it's about 3 times as expensive (for equivalent amount it can oxidize). Usually in a residential pool that has lower bather load, chlorine and sunlight alone are enough to keep up and have minimal Combined Chlorine (CC). If your pool isn't in full sun, then that can slow down some of the oxidation of bather waste.

The more usual options for commercial/public or other high bather load pools are to use UV or ozone to supplement in a more automated way than manually adding MPS. This is especially important for indoor high bather load pools since they have the worst combination with no sunlight and generally poor air circulation. Enzymes are another option (something like Orenda CV-700, ORB-3 Pool Enzymes Plus, K4Products Eco Pool Enzymes Plus, Pool Enzyme 5100, etc.) as these help oxygen oxidize urea and other bather waste usually cutting down on chlorine demand and disinfection by-product.
You can also try to enforce having people not pee in the pool. Ben Powell has said that when he enforced a rule of everyone getting out of the pool for 5 minutes every hour, that the chlorine demand and CC issues went way down, probably because people would use the bathrooms instead of the pool. Of course, that may not be practical in your situation (for a humorous look, see this video).

Richard

Thanks Richard. LOL at the youtube video.

We do indeed have a heavy bather load and it's a smaller pool as well. The pool is south facing so we have full sun all day.
I forgot to mention in previous posts, we do use Pool Perfect Enzyme as well. I wasn't convinced it made much of a difference until I let it run out at the end of the season last year and had about a month without it. I won't let that happen again. I have that on automation as well.

Tonights readings were
FC 16.4
CC 0
Ph 7.4
Alk 100
CYA 35ish
I brushed the heck out of the pool too and scrubbed any corners that might be hiding things.
Fingers crosses we have this beat soon.
In the 5 years we've had this pool, this has been only the second time I've had issues like this. Other issues, yes but not this particular kind.
I owe that to this forum. I know I can come here and find help without being made to feel stupid or like I am wasting someone's time.
Thanks
 

deenamccauley

LifeTime Supporter
May 29, 2007
177
Alberta, Canada
Ugggh, I'm getting frustrated. Is this just taking a long time to clear or am I missing something.
This morning readings
TC 14.4 (2 ppm drop from last night)
CC .2
PH 7.1
Alk 110
CYA 30ish

Water is definately clearing but still rather dull. Keeping the levels up again today. Anyone have any other suggestions? Or do I just have to practise patience and perserverance.
 

deenamccauley

LifeTime Supporter
May 29, 2007
177
Alberta, Canada
Still seeing a drop ion FC over night. This time it was 4 ppm. I got interrupted in the middle of that test so there could be some user error but there still is a definate drop.
CC .2
PH 7.1
Alk 110
CYA 30ish
Poor water is clearer but still not crystal clear. I'm vacuuming and brushing every day, back washing every other day as needed.
Do I keep the FC at shock level? I have had it there since the 12th, so about 4 days.
I did add MPS yesterday so that could be the CC I'm reading. I had 0 CC all day yesterday.
 

deenamccauley

LifeTime Supporter
May 29, 2007
177
Alberta, Canada
Ok, I'm an idiot and have been doing this all wrong. Although I have been testing at night, 30 minutes after my last chemical addition, I am testing way after the sun comes up. (Which is about 4 am, here) I test at 8 am. Also my automated chlorinator is running at night as well which would alter results. I really can't shut this off because I am semi-public pool.
Would this account for my FC loss?
And if that is the case, then can I assume that with a CC of .2 that I have beat this problem?
 

Bama Rambler

Mod Squad
TFP Expert
LifeTime Supporter
Jun 22, 2009
23,062
SouthWest Alabama
The absence of CC's doesn't mean there's not a problem. The only way to know for sure is to do the OCLT (overnight chlorine loss test) properly. Why can't you shut the chlorinator off for a night? Even if you have to close the pool one night I think it'd be the wise thing to do. In fact closing the pool for that night would be a good thing. Having people in the pool will also affect the OCLT.
 

deenamccauley

LifeTime Supporter
May 29, 2007
177
Alberta, Canada
Bama Rambler said:
The absence of CC's doesn't mean there's not a problem. The only way to know for sure is to do the OCLT (overnight chlorine loss test) properly. Why can't you shut the chlorinator off for a night? Even if you have to close the pool one night I think it'd be the wise thing to do. In fact closing the pool for that night would be a good thing. Having people in the pool will also affect the OCLT.
Because we are a semi private/public pool and have automated feeders we are supposed to run it 24/7 as well as the pump.
I could close the pool for a day but I would have some very unhappy campers. I will do that tonight though and retest.
I do not however want to get up at 6 am to test before the sun comes out, anyway around that? Does a couple hours make that much difference?

My other thought though is if this is algae or bacteria or whatever.....and I have kept my chlorine levels to shock value why is it not clearing? Am I missing something here in the process?
How long do you need swimmers out of the pool to get an accurate read on OCLT? We do close our pool from 8 pm to 10 am, so it's not like it is never empty.

Thanks for your help.
 

Bama Rambler

Mod Squad
TFP Expert
LifeTime Supporter
Jun 22, 2009
23,062
SouthWest Alabama
Yes, a couple of hours can make quite a difference. Since you already close the pool from 8pm till 10am, all you need to do is shut off the auto feeder. Leave the pump running.
 

deenamccauley

LifeTime Supporter
May 29, 2007
177
Alberta, Canada
Ok, this mornings readings. The Chlorinator was off from 8 pm to 8 am.
Last night readings, 1/2 hour after last chemical addition
FC 15.8
CC 0
This morning
FC 14.8
CC .3
PH 7.3
Alk 110
CYA 30
These readings were taken 2 hours after sunrise on a very cloudy day, not sure if that makes any difference or not.

So if I have been keeping my pool at shock levels for my CYA level for about 5 days now....why is this not clearing?
 

Bama Rambler

Mod Squad
TFP Expert
LifeTime Supporter
Jun 22, 2009
23,062
SouthWest Alabama
The fact that you lost 1ppm FC and have .3ppm CC's mean you have organics consumming the chlorine and you need to keep it at shock level. It's going to be hard to shock it properly with it being in use every day. You're just going to have to keep at it.
 

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