Q on chlorine after dark

[poolgirl10]

Hi--
Question on whether once you add chlorine after dark to a certain number, can when you check later it be higher?

Last two nights this has happened during shock process.

Added at 9:40pm from 23 to 28. when i checked 1 hour later it was 30.5.. figured operator error.

next night. at 7:40 added from 20.5 to just over 25. at 9:50 it was 27.5 checked again same 27.5

is it all about how much 0870? i always use heaping spoonful, and some always on bottom of vile

strange??

 

[Bama Rambler]

If you've added in the past and it's worked out correctly, I'd suspect you got a little stronger bleach than you expect. If the bleach is really fresh it may be a little stronger than the label lists.

 

[jblizzle]

Could be that either the pool is smaller than you think or the bleach is stronger than you think.

Sounds like you are using enough powder, but that would not make it read high anyway.

Posted from my Droid with Tapatalk ... sorry if my response is short

 

[UnderWaterVanya]

Describe the details of how you add and how you test. Here's my process:

1. I add bleach in front of a return while the pool pump is running.
   I wait at least 1 hour - sometimes more - while the sun is off the pool.
   I collect my sample from the deep end near my ladder where I think circulation is only OK.
   Sample is collected by rinsing the sample cup, and sticking the cup in inverted.
   I reach in as far as I can and then flip the cup and bring it up.
   I test using the FAS-DPD test from my TF100 using the 10ml sample directions.
   (Rinse with pool water, dump, refill to 10ml, add a heaping DPD measure, etc.)
   I constantly stir and typically (unless shocking) drop 1 drop at a time very quickly.
   I slow down when the solution starts to fade to light pink.
   If the solution clears I wait a few seconds and then if it stays clear I add the R0003 reagent.
   If the solution then turns pink I test how many drops are needed to turn clear (CC's).

Do you suspect poor circulation perhaps? If you do - try brushing the entire pool while waiting for the mixing to occur - this should help distribute the bleach more rapidly.

 

[poolgirl10]

Thanks for advice-didnt think about the chlorine could be more intense. although it is 10% bought at walmart of meijer so wouldnt think so...as i assume it sits around all summer in back of store.

I do the same procedure when getting my sample too.. its in deep end, in between to returns, try to do with them not on, but sure I have at times.

I have lost just over 1 and no CC. I wondered it auto cover changes this process at all? close after last check, open in morning and then wait 10-30 minutes before i test.

 

[poolgirl10]

btw-i run the pool pump 24/7

 

[Bama Rambler]

The cover shouldn't change anything.

They could have had to order new stock and gotten a fresh batch so it could be stronger. Like I said, if you've added before, and it's come out to what you expected it to, and now it's overshooting a little I'd blame it on the bleach.

 

[UnderWaterVanya]

Still confused. Is this a higher result than you expect - or is this a situation where the morning measurement is higher than the last night time measurement?

Is this what happens?
Baseline Measurement - Add Chlorine - Wait 30-60? mins - Take Measurement X - Wait overnight - Take Measurement Y; Y > X

Or is this is situation where X is the predicted value and Y is the measured value - so that you suspect that the chlorine is stronger than expected?

 

[poolgirl10]

Hi-

I added 39-60 before last check thinking I was adding to 25 but came out 27.5 twice for last check at night. -this was last night. this morning it was like 25.5. my confusion was last night how could it be higher when i had asked it to go to 25. Y was not higher than X. so i guess it was a higher concentration of chlorine than the 10%

so because of 2 loss shocking still. although this was process i started because of a bit hazy and had had water mold. not algae. thought about stopping today letting it go back to top regular shock-10 and watching.

did add back to 25 at 12;20
did this help you?
thoughts?

 

[UnderWaterVanya]

my confusion was last night how could it be higher when i had asked it to go to 25. Y was not higher than X. so i guess it was a higher concentration of chlorine than the 10%

...did this help you?

Yes. It could be that the concentration was slightly higher than previous use of the product since the loading doc temps and outside temps in general are falling. It's also possible if you haven't had a lot of experience with this particularly product that your measurements of the pool are slightly off and the previous bleach/chlorine you used is a little weaker than expected.

I'm not sure what to advise on the shock - there's nothing wrong with either approach as far as I can tell. Keeping the higher shock level may help clear up the OCLT quicker or it may not.

 

[poolgirl10]

Thanks for the help! Always nice to have someone to help along the way! you guys are great!

as of now still shocking. if still 2 tomorrow i may go back to 10 and see.

your thoughts on pool size and cooler temps makes sense. the pool store sheet says 23,200 but have been doing 24,000.

 

[Bama Rambler]

I wouldn't stop shocking until you pass the OCLT.

 

[UnderWaterVanya]

so because of 2 loss shocking still. although this was process i started because of a bit hazy and had had water mold. not algae. thought about stopping today letting it go back to top regular shock-10 and watching.

What is the CYA level again? Reading the above I assumed you were torn between Mustard Algae shock and regular shock levels - sounds like your CYA is pretty low if 10 is your regular shock level. Or did I misunderstand the post?

Thanks for the help! Always nice to have someone to help along the way! you guys are great!

Welcome - I'm a relative newbie myself; trying to pay back to the site that helped me.

as of now still shocking. if still 2 tomorrow i may go back to 10 and see.

More confused now. Is 10 shock or not - need that CYA level to grasp what the decision is that you are trying to make.

 

[poolgirl10]

Sorry-

I am talking about regular FC range. I have CYA of 65ish, hope to work on as this process wraps up. i meant take back to regular FC level but keep at 10 and watch. I read someone with pink slime has done this when she got to 2 ppm and it worked in time.

i had been doing the pool store way (2nd full summer) hazy water, they said shock everytime i went in, not telling me that the sticks i was putting on high in chlorinator were just making matters worse!

 

[jblizzle]

a FC of 2ppm is way to low for your CYA. And shock level is much higher than 10ppm. Read some more of Pool School, specifically the CYA/ FC chart.

Posted from my Droid with Tapatalk ... sorry if my response is short

 

[UnderWaterVanya]

I am talking about regular FC range. I have CYA of 65ish, hope to work on as this process wraps up. i meant take back to regular FC level but keep at 10 and watch. I read someone with pink slime has done this when she got to 2 ppm and it worked in time.

Gotcha. I would most assuredly keep shocking then. A sand filter takes a while to clear up the cloudiness and until you pass the three criteria I wouldn't let it fall. The problem is that while it may look perfect at some point it could also be on the verge of tipping over the edge to problems.

If you want to look at speeding up the process of getting rid of the cloudiness you can consider adding some DE to your Sand Filter.

i had been doing the pool store way (2nd full summer) hazy water, they said shock everytime i went in, not telling me that the sticks i was putting on high in chlorinator were just making matters worse!

Ugh - it is easy to think of them as greedy and intentionally misleading but I think it is a total lack of knowledge and a matter of odds. Much of the time the traditional model works for one reason or another, but when it breaks - it is really rough to get fixed and the lack of science makes the solutions offered up just a series of stabs in the dark.

 

[poolgirl10]

thanks-

i have been clear really since day 2 of bleach added. thats why its tough to hang on with shock but I am. It has been 2 weeks. so has looked free of water mold quickly and clear, no CC or very low and just the 2ppm overnight loss!