Another SLAM question

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picklebush

Silver Supporter
Jul 28, 2018
54
Hebron, Texas
I've taken over my pool since July of last year from my prior pool Tech. Back then I discovered the CYA was about 230ppm and the chlorine was 15 ppm.

I've learned a lot in the last 10 month and yes I do have the Taylor FAS-DPD kit, so I'm trying to be on top of all my chemicals. However, my CYA is still hovering at 60 and my pool builder says because it was so high for so long that the plaster soaks it up and even a complete replacement won't bring it down much. OK

So Sunday night this week I decided to go ahead and do the SLAM method. With 60 CYA, my target chlorine is 27ppm but I don't think I can ever get there. The past three days I've been able to get the chlorine up to about 12.5. And no higher. I am using the POOL MATH app.

Some other notes, yes I've been running my pool pump at 40 gpm, so my small pool turns over every four hours. It's been running nonstop since Sunday. Other chemicals are in check, ph, TA, Calcium Hardness. I've gone through probably 3 cases of liquid chlorine now. I add it in the morning and evening. I was adding it during the day time too but decided it just evaporates too fast.

My DE filter doesn't appear to be clogged. It's only 50% to "clean" indicator on the gauge. However, now I'm starting to think I need to stop the pump and disassemble it and clean it anyway.

I guess my question is, is it OK that I don't get to the 27ppm target if I am able to pass the OCLT test?

We are in North Texas and the sun eats my Chlorine like gasoline on a fire.
 
picklebush said:
I've been able to get the chlorine up to about 12.5. And no higher. .... I've gone through probably 3 cases of liquid chlorine now.
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As liquid chlorine ages and/or is exposed to heat or UV, it loses potency. How old is the chlorine you've been adding, and how have you been storing it?

This may help to decode the date stamps if they're not clear: Chlorine Date Code Decoder - Further Reading
 
DrewLG said:
As liquid chlorine ages and/or is exposed to heat or UV, it loses potency. How old is the chlorine you've been adding, and how have you been storing it?

This may help to decode the date stamps if they're not clear: Chlorine Date Code Decoder - Further Reading
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I just bought it this week from Leslies. The most expensive place I could find LOL. I checked the box and it looks like February it was made. But I am keeping my chlorine inside until I need it. So it's stored at regular household temp. I have no idea what conditions it was stored prior to me getting it yesterday and prior just before, maybe Saturday.
 
Texas Splash said:
Actually, with a CYA of 60 your SLAM FC level is 24, so you are good. Don't worry about water turnover. No benefits to that concept. Just maintain the FC of 24 and follow the SLAM Process page for best success.

Good luck!
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But that's what Im saying. I cannot even get to 24. I'm at 12.5. How can I get to 24? I have read the SLAM page many times and will review again. There is a few leaves in my polaris 280. I guess I could get that out, but it's not significant amount. Otherwise not a drop of anything in the pool. I have been skimming and brushing everyday.
 
picklebush said:
I checked the box and it looks like February it was made. But I am keeping my chlorine inside until I need it. So it's stored at regular household temp. I have no idea what conditions it was stored prior to me getting it yesterday
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A gallon of full-strength 12.5% liquid chlorine will raise FC in 10,000 gallons of water by 12 ppm. So the three cases (which I assume hold 4 gallons each) of liquid chlorine that you've poured into your pool should have been sufficient to raise FC by 144 ppm.

Some possible causes of the failure to measure anything higher than 12.5 ppm: Your cases of liquid chlorine hold much less than 4 gallons, your testing is grossly inaccurate, your chlorine has degraded substantially, your pool is many times larger than the 10,000 gallons shown in your signature, your pool is filled with something other than water.

How are you testing chemical levels?
 
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DrewLG said:
A gallon of full-strength 12.5% liquid chlorine will raise FC in 10,000 gallons of water by 12 ppm. So the three cases (which I assume hold 4 gallons each) of liquid chlorine that you've poured into your pool should have been sufficient to raise FC by 144 ppm.

Some possible causes of the failure to measure anything higher than 12.5 ppm: Your cases of liquid chlorine hold much less than 4 gallons, your testing is grossly inaccurate, your chlorine has degraded substantially, your pool is many times larger than the 10,000 gallons shown in your signature, your pool is filled with something other than water.

How are you testing chemical levels?
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thank you for the reply. I have a Taylor K2006. I am using the FAS-DPD. I fill the vial up to the 10mL (as it says I can do), then add the 2 dippers of powder, 0870. Then I add the R0871 dropwise and count drops. Please tell me this is OK LOL

So either Leslies is selling me Crud Chlorine, which is hard to imagine it's that bad. Or I'm an idiot, or both lol (how can I test this chlorine? is there a way w my kit?)

I think my pool is about 10K. I attached a photo. Hard as heck to measure it. My pool builder that resurfaced, tiled and coped it, said maybe closer to 13K, but when I used chemicals at that range, I kept overshooting it, so I backed down to 10K and had better results w the chemicals. its only barely 5 feet deep in middle and sides are probably 3 foot deep. A small pool. Hot tub is a big oversized imho.

I'm open to anything at this point. I guess I must be using the kit wrong, but I always look at the instructions in the lid. See photo attached.

Thanks again for all your help.
 

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With your pump running for 30 minutes or more, test your FC after sampling at 18" below the water surface with a clean bottle. Assuming you are near 12ppm FC, next pour 1 gallon of 12.5% in front of the return flows. Let your pump run for 30 minutes more and test again, same depth same place. Report back your FC numbers. :testkit:
 
picklebush said:
I have a Taylor K2006. I am using the FAS-DPD. I fill the vial up to the 10mL (as it says I can do), then add the 2 dippers of powder, 0870. Then I add the R0871 dropwise and count drops. Please tell me this is OK LOL
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That's ok. You don't need so much powder, but it isn't hurting your test results.

picklebush said:
So either Leslies is selling me Crud Chlorine, which is hard to imagine it's that bad.
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Not hard for me to imagine.

It doesn't seem likely that the pool actually holds 100K gallons, or that it contains something that instantly consumes all but 12.5 ppm of chlorine, or that your Taylor reagents are bad in a way that nobody's ever seen before. Meanwhile, if the chlorine actually has degraded significantly, that would produce exactly the symptoms you describe.

picklebush said:
how can I test this chlorine? is there a way w my kit?
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Not easily. You'd have to dilute the liquid chlorine 10,000 to 1 to be able to measure its concentration with your test kit, and errors in that process might overwhelm the results anyway.
 

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Oly said:
With your pump running for 30 minutes or more, test your FC after sampling at 18" below the water surface with a clean bottle. Assuming you are near 12ppm FC, next pour 1 gallon of 12.5% in front of the return flows. Let your pump run for 30 minutes more and test again, same depth same place. Report back your FC numbers. :testkit:
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Ok it's been running since Sunday lol. I'll go do this now. Yes, I dip my arm way down to get the 18" depth. Be back soon! Thank you!
 
DrewLG said:
That's ok. You don't need so much powder, but it isn't hurting your test results.



Not hard for me to imagine.

It doesn't seem likely that the pool actually holds 100K gallons, or that it contains something that instantly consumes all but 12.5 ppm of chlorine, or that your Taylor reagents are bad in a way that nobody's ever seen before. Meanwhile, if the chlorine actually has degraded significantly, that would produce exactly the symptoms you describe.



Not easily. You'd have to dilute the liquid chlorine 10,000 to 1 to be able to measure its concentration with your test kit, and errors in that process might overwhelm the results anyway.
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Its got to be the chlorine. I just tested. I was at 12.5 FC this morning and now down to 8.5. I'm running a new test with a fresh 128 gallons right before the return. will test in 30 minutes, same spot, same depth. Here is a photo of the only date stamp i can find on the Chlorine box from leslies.
 

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You have Pinch a Penny stores in your area. Most sell liquid chlorine in refillable car boys. Check on that.
 
Test after 30 minutes and report a) fc test before, b) amount of LC you added, c) FC after 30 minutes. I think your pool volume may be off. What are the general dimension of the pool. Length, width at widest, width at narrowest, Depth (deep and shallow if you have it, but it looks like you have constant depth.
 

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