Started SLAM process to start the year off and WAY over shot.

rjackson87

Gold Supporter
May 16, 2024
33
New Lenox - Illinois
Pool Size
21000
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
I opened the pool this year all by my lonesome this time with it being our 3rd opening, and not being present for the first one. The water was little cloudy with not too much gunk in the pool.

My first readings came in at the below:
  1. FC = 1
  2. PH = 7.8
  3. TA = 80
  4. CYA = 70
  5. CH = 250
  6. Salt = 3600
  7. Borates = 46
  8. Water temp = 50F
I added 5 Gallons of 12.5% this afternoon, and just tested again. My FC shot to 42, and when I did the Pool Math 5 gallons was a little over what was recommended. I didn't think it would jump that much. I buy my FC at a local family owned place who has giant vats and supposedly makes it themselves. I'm wondering if the % may have been higher than 12.5.

Should I be worried, should I do anything to neutralize, or just let it burn off on it's own with the auto-cover open?

Last year, traditionally when my auto-cover is closed FC has burned off SUPER quick.
 
How are you testing your water? Your signature indicates TF-pro...but it does not test borates. I'd be VERY surprised your borates are 46...which leads me to not trust the other levels.
Assuming everything else is accurate, the 42 is surprising. 5 gallons would raise your FC by 28.
It is not likely your LC is higher than 12.5%
It is more likely testing error.
Clean and dry your test vial with Rubbing Alcohol and retest.
Go slow, hold the reagent vertical, squeeze slowly, so the drops form and drop under their own weight. Swirl, then drop again. Go slow.
Report back.

Overshooting once is not an issue.
 
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Are you doing the FAAS/DPD chlorine test with a 10 ml sample or 25 ml sample?

1 drop = 0.5 ppm or 0.2 ppm?

42 ppm is 84 drops or 210 drops?
 
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How are you testing your water? Your signature indicates TF-pro...but it does not test borates. I'd be VERY surprised your borates are 46...which leads me to not trust the other levels.
Assuming everything else is accurate, the 42 is surprising. 5 gallons would raise your FC by 28.
It is not likely your LC is higher than 12.5%
It is more likely testing error.
Clean and dry your test vial with Rubbing Alcohol and retest.
Go slow, hold the reagent vertical, squeeze slowly, so the drops form and drop under their own weight. Swirl, then drop again. Go slow.
Report back.

Overshooting once is not an issue
I am thinking I lost count or something along the way, going to test again in the AM.

I’m using TF Pro and couple other items for the borate testing following a process i found on here. Purchased the BTB and Mannitol powder and doing the 50ml test.

For FASDPD I do the 10ml test.
 
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I am thinking I lost count or something along the way, going to test again in the AM.

I’m using TF Pro and couple other items for the borate testing following a process i found on here. Purchased the BTB and Mannitol powder and doing the 50ml test.

For FASDPD I do the 10ml test.
Outstanding!

Maybe a loss of count. Please take care.
10mL sample, each drop is .5 FC. Each 10 drops is 5FC.

Your Salt loss and Borates loss, in your pool math logs, are consistent...as to water loss.

Clean your vials with rubbing alcohol and dry.
Test again. Keep your reagent vertical and slowly squeeze each drop, allowing the drop to drop under their own weight.
Report back. Great job on the test kit and testing!

One other thought...how old are your reagents?
 
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Use a 5 ml sample and 1 drop = 1 ppm at very high FC levels.

It is easy to introduce big testing errors by creating small drops with a high drop count.

Test slowly and let each drop form on the tip and fall off naturally. It will take time to run a test with 40 or 80 drops.
 
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I am thinking I lost count or something along the way, going to test again in the AM.

I’m using TF Pro and couple other items for the borate testing following a process i found on here. Purchased the BTB and Mannitol powder and doing the 50ml test.

For FASDPD I do the 10ml test.
In addition to above, when the FAS-DPD drops and the sample turns clear, stop the test and record the results. If you wait a bit, the sample may turn pink again and if you add more drops, it’ll lead to falsely high FC test result.
 
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It is easy to introduce big testing errors by creating small drops with a high drop count.
The testing error is the same for all sample sizes, regardless of the drop count, or drop size.

Taylor testing error is +/- 1 drop per 10.
Assume your FC is 30.
5mL test would be 30 drops, +/-3 drops or +/-3 FC.
10mL test would be 60 drops, +/-6 drops or +/- 3 FC.
25mL test would be 150 drops, +/-15 drops or +/- 3 FC.

Let's further assume that drops are 10% smaller.
5mL test, 33 drops, FC = 33.
10mL test, 66 drops, FC = 33.
25mL test, 165 drops, FC = 33.
 
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Thank you all, I didn't get a chance to read the forums this morning, but will test again later tonight using some of the suggested methods, i.e., 5mL. Also I'll go a little slower with the drops, I usually squeeze slowly and let them fall under their weight with the bottle vertical -- I think I'm doing it right!?

This morning when I tested I came up with 37.5 FC and .5 CC.

I had closed the auto-cover almost completely overnight with maybe a foot open on the end to let any "gas" escape. Not sure if this is a real thing or not, but the auto-cover people mentioned that if there is high chlorine in the pool you may want to leave it cracked.

The water loss makes sense because when we closed the pool we drained a decent amount to get the pool below the sun ledge. The pool company who I have do the closing requests this because I don't think they want to get wet? I also backwashed the filter for about 10 minutes after I primed the sand filter which took some time as well.

For reagent age, I pushed my kit last year in the summer. I purchased more FAS-DPD powder and drops throughout the year because of having to SLAM for a pretty extended period of time. Then I started testing FC a ton to try to determine best % to run the SWG at.

Pictures I took yesterday, during the day and at night. It's very clear at least :).

419_Day.PNG
0419_Night.png
 
Keep your cover open during the day until your FC gets down to normal levels.
 
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