Brand New Pool Owner - iChor 30 FC Reading Very High

ntpd

Active member
Apr 27, 2020
37
NJ
Hi there -

Brand new pool owner.... 8,000 gallons, fiberglass, iChor 30 SWG, Pentair Superflo pump, and Pentair SD40 sand filter . I've started to try and learn chemistry and read as much as I can here, but I seem to have a rare problem; my FC is testing very high. I am testing using Aquachek test strips, and have purchased a more reliable test kit, but it hasn't arrived yet.

About 10 days ago, when the installation company came to clean the pool and "hand us the keys" they added 1 gallon of liquid shock, and set the iChor at 33%. Should I dramatically decrease the iChor output and monitor daily? Should I turn it to 0?

Thanks - I really appreciate the help and forgiveness if I have asked dumb questions. If I'm missing anything that would be valuable, please let me know.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
33,078
Laughlin, NV
There is no Taylor K-200. Is it the K2005 or K2006C?

Waterguru is fine for monitoring. Just do not use the data for chemical adjustments.
 

mknauss

Mod Squad
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May 3, 2014
33,078
Laughlin, NV
Great. That kit is fine. Very small bottles of the reagents you will use the most. But will get you started and then you can order refills.
 

mknauss

Mod Squad
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Bronze Supporter
May 3, 2014
33,078
Laughlin, NV
If you trust the strips, turn off the iChlor for few days.

Me, I would adjust the iChlor so it is creating 2 or 3 ppm FC per day. Use PoolMath to determine that.
 

ntpd

Active member
Apr 27, 2020
37
NJ
If you trust the strips, turn off the iChlor for few days.

Me, I would adjust the iChlor so it is creating 2 or 3 ppm FC per day. Use PoolMath to determine that.
Ok - I got my K2006C (I upgraded) and now have real test results. I'm sure there is minor variations in them as it was my first time using this, but I tried my best to adhere to directions/

FC 10.0 (took me 50 drops at 25mL)
CC 0
pH 7.6
TA 90
CYA 42 (I'm least confident in this measure, the black dot was really hard to see around 50)
Salt 3398
Temp 58º

I have had my SWG at 0% for about 48 hours now. The next two days will be quite rainy here in NJ as well.
 

mknauss

Mod Squad
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May 3, 2014
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Laughlin, NV
Great job on the test results.
Round up your CYA To 50 ppm.
Next time use a 10 ml water sample for FC testing. One scoop of powder and each drop of reagent to clear is 0.5ppm FC.
I assume that salinity is from the iChlor?
Have you turned the SWCG off or just reduced the setting?
 

ntpd

Active member
Apr 27, 2020
37
NJ
Great job on the test results.
Round up your CYA To 50 ppm.
Next time use a 10 ml water sample for FC testing. One scoop of powder and each drop of reagent to clear is 0.5ppm FC.
I assume that salinity is from the iChlor?
Have you turned the SWCG off or just reduced the setting?
Yes - salinity is from the iChor... I have not turned it off, I have simply reduced the output to 0%.

Would you mind elaborating on the CYA round-up? If it's in the ABCs, or elsewhere, I'll read there. Just want to make sure I understand!
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
33,078
Laughlin, NV
From Test Directions in Pool School:
The safest way to ensure you have enough Free Chlorine for your CYA level is to round up your CYA result. If the endpoint of the CYA test is between 50ppm and 60ppm record that result as 60ppm and use that to determine your required Free Chlorine level.

My version:
The vial is in logarithmic scale. So it is not viable to interpolate between the lines. Just use the whole numbers, such as 50, 40, 30, ....
 

ntpd

Active member
Apr 27, 2020
37
NJ
From Test Directions in Pool School:
The safest way to ensure you have enough Free Chlorine for your CYA level is to round up your CYA result. If the endpoint of the CYA test is between 50ppm and 60ppm record that result as 60ppm and use that to determine your required Free Chlorine level.

My version:
The vial is in logarithmic scale. So it is not viable to interpolate between the lines. Just use the whole numbers, such as 50, 40, 30, ....
Perfect - I appreciate that, because of all of the tests, that felt the least exact/scientific. Your logic is quite sound.
 

ntpd

Active member
Apr 27, 2020
37
NJ
From Test Directions in Pool School:
The safest way to ensure you have enough Free Chlorine for your CYA level is to round up your CYA result. If the endpoint of the CYA test is between 50ppm and 60ppm record that result as 60ppm and use that to determine your required Free Chlorine level.

My version:
The vial is in logarithmic scale. So it is not viable to interpolate between the lines. Just use the whole numbers, such as 50, 40, 30, ....
If I am reading the FC/CYA chart right, I should increase my CYA to 70, with a target FC of 5.... that said, it feels counterintuitive to increase CYA if it's purpose is to "protect" FC.
 

ntpd

Active member
Apr 27, 2020
37
NJ
We have found that a higher CYA is best when using a SWCG. You can read about it in Pool Water Chemistry

You can leave the CYA at 60 if you wish. Just be watchful of the FC dropping more during the day due to UV impact.
Got it. I will likely see if I can burn off some of this FC first and then raise CYA once I have it dialed in.
Feel free to tell me if that’s a terrible idea though :)
 

ntpd

Active member
Apr 27, 2020
37
NJ
To be honest your FC is not high. With a little sun it will go down quickly. Keep an eye on it.
Thank you for your perspective. This is helpful. I need to kick the idea that those test strips were maxed out. I feel like I’m going to melt if I go in, but clearly I’m not that far off ideal.