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Thread: IC40 reading low but water tests at 3400 ppm

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    IC40 reading low but water tests at 3400 ppm

    So I have been pouring liquid chlorine into my pool for weeks now and haven't been able to keep my chlorine up. My IC40 was showing that the salt was low so I added a bag of salt here or there (didn't have a good saltwater test kit at the time so I was relying on the IC40 to tell me when to stop) would wait a couple of days to see if it went green before adding another. I think that I added a total of 3 bags before it turned green for a couple of days then back to red. So I ordered the Taylor Sodium Chloride test kit to see where the salt actually is. The test kit was literally just delivered so I ran out and tested the water and it comes in at 3400 (I was a little afraid that it was going to be way high. I am in the process of cleaning it now so we will see if it gives me different lights here in a bit. If not and knowing that the salt content is 3400, should I try to recalibrate the current IC40 before replacing? It's not quite 2 years old.

    Other readings

    FC: 4
    PH: 7.2 (lowered it by adding acid this morning
    TA: 110
    CHA: 450

    I have been waiting to figure out exactly what my salt is so I can determine my next step.
    My Pool Build Thread: 21 x 40 Freeform Gunite Pool, 12" Tanning Ledge, 3.5 shallow graduating to 4.5, 8.5 deep end, 4' Waterfall which doubles as a diving ledge with 6' x 4' Grotto underneath, 670 sq. ft., 106 Linear ft., Rock Salted Concrete Deck, Pentair 520 Filter, Intelli flow 3 HP VS pump, (4) Color LED lights, Intelli-Chlor SWG, Hot Springs Vanguard Hot Tub with ACE and BT Sound System, ODK, TF100

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    Re: IC40 reading low but water tests at 3400 ppm

    I have an IC-40 (and have had major issues: Intellichlor IC40 Low Salt but reads fine). I finally learned how finicky this thing is when the season started to end. Basically, you have to clean this thing about every 2 months for the sensor to work correctly, so start with a good cleaning. Second, I'm not sure what weather there is like, but at water temps below 65 or so degrees, you can't trust the light on the IC-40. It doesn't seem to update the readings for a long time (at least 6 hours, not sure if even longer), so you may need to manually power it down/up to get it to read again when the water temp rises a bit.

    Either way, definitely do not dump salt in the pool based on the light - always independently test.
    20x40 28kgal in-ground vinyl built 2011, liner replaced 2017
    Pentair Tagelus TA60D sand filter, Pentair SuperFlow 1HP pump, Intellichlor IC40 SWG, Dolphin Active 30i
    City water, TF-100 test kit + speedstir.
    Recommended Levels | Chlorine/CYA Chart | SLAM

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    Mod Squad Jimrahbe's Avatar
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    Re: IC40 reading low but water tests at 3400 ppm

    dr,

    While you are right on about the unit only updating every 12 hours and to not always trust the salt reading it provides, your idea that you have to clean the cell every two months is not at all true.

    If you keep your water per the TFP guidelines inspecting your salt cell once of a year is plenty. And just because you inspect it, does not mean you have to acid clean it.

    Cells get a lot of build up on the plates because of bad water chemistry, not because the cell is bad.

    The main problem with the Intellichlor is its temperature sensor, which is not all that robust in my opinion. When the temperature sensor is off, or bad, it causes the salt readings to be inaccurate.

    Soonerwing, there is no cell calibration for the IC40, except for very very old cells...


    Here is a test, provide by JamesW, which tests the temp sensor.

    Pressing and holding the “More” button launches the System Status Mode. When the lights finish scrolling, the percent lights indicate hours of usage in 1,000s. For example, if the 40% light lights, that indicates 4,000 hours.

    Version 3.1 on adds the ability to determine system temperature. Pressing the “More” button after the display shows 1,000s of hours of usage, will show temperature as follows:

    Lights…………….....………Temperature
    No LEDs………….…..………Below 30F
    40%..........................36 to 45F
    40% and 60%............46 to 55F
    60%..........................56 to 65F
    60% and 80%............66 to 75F
    80%.........................76 to 85F
    80 and 100%............86 to 95F
    100%.......................96 to 99F
    100% blinking……..….over 99F
    All LEDs blinking……...Sensor bad

    The temperature sensor is a 10k thermistor. Its resistance varies based on the temperature. The way it varies is known precisely. So the box measures resistance in ohms and calculates the temperature.

    If the thermistor fails in a way that’s obvious to the software, the software will ignore the thermistor and use 75 degrees F as the temperature.

    When using 75 as the default temperature, the salinity will be miscalculated by the software for any water temperature other than 75 F.

    Thanks,

    Jim R.
    Finished in 2015 - 17K Gal, IG, 20' x 25' Almost Rectangular Pool, Pebble finish, three rockport water falls. Pentair Equipment: EasyTouch 4, IC40 SWG, 3 HP VS Pump, CCP520 Cartridge Filter.
    TF100 with SpeedStir and SampleSizer, ColorQ Pro 7, Dolphin Premier Robot Cleaner, added Screen Logic 2, added small 3 person Caldera Spa.

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    Re: IC40 reading low but water tests at 3400 ppm

    Quote Originally Posted by Jimrahbe View Post
    While you are right on about the unit only updating every 12 hours and to not always trust the salt reading it provides, your idea that you have to clean the cell every two months is not at all true.

    If you keep your water per the TFP guidelines inspecting your salt cell once of a year is plenty. And just because you inspect it, does not mean you have to acid clean it.

    Cells get a lot of build up on the plates because of bad water chemistry, not because the cell is bad.
    Thanks for the clarification Jim. I didn't mean to imply that the cell itself needed cleaning, but doing an acid clean seemed to help the temperature sensor work correctly in my case. Granted, I inherited some very badly balanced water, so that could have been the culprit. Or it could have been a lucky coincidence that it worked after a cleaning.
    20x40 28kgal in-ground vinyl built 2011, liner replaced 2017
    Pentair Tagelus TA60D sand filter, Pentair SuperFlow 1HP pump, Intellichlor IC40 SWG, Dolphin Active 30i
    City water, TF-100 test kit + speedstir.
    Recommended Levels | Chlorine/CYA Chart | SLAM

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    Re: IC40 reading low but water tests at 3400 ppm

    Quote Originally Posted by Jimrahbe View Post
    dr,

    While you are right on about the unit only updating every 12 hours and to not always trust the salt reading it provides, your idea that you have to clean the cell every two months is not at all true.

    If you keep your water per the TFP guidelines inspecting your salt cell once of a year is plenty. And just because you inspect it, does not mean you have to acid clean it.

    Cells get a lot of build up on the plates because of bad water chemistry, not because the cell is bad.

    The main problem with the Intellichlor is its temperature sensor, which is not all that robust in my opinion. When the temperature sensor is off, or bad, it causes the salt readings to be inaccurate.

    Soonerwing, there is no cell calibration for the IC40, except for very very old cells...


    Here is a test, provide by JamesW, which tests the temp sensor.

    Pressing and holding the “More” button launches the System Status Mode. When the lights finish scrolling, the percent lights indicate hours of usage in 1,000s. For example, if the 40% light lights, that indicates 4,000 hours.

    Version 3.1 on adds the ability to determine system temperature. Pressing the “More” button after the display shows 1,000s of hours of usage, will show temperature as follows:

    Lights…………….....………Temperature
    No LEDs………….…..………Below 30F
    40%..........................36 to 45F
    40% and 60%............46 to 55F
    60%..........................56 to 65F
    60% and 80%............66 to 75F
    80%.........................76 to 85F
    80 and 100%............86 to 95F
    100%.......................96 to 99F
    100% blinking……..….over 99F
    All LEDs blinking……...Sensor bad

    The temperature sensor is a 10k thermistor. Its resistance varies based on the temperature. The way it varies is known precisely. So the box measures resistance in ohms and calculates the temperature.

    If the thermistor fails in a way that’s obvious to the software, the software will ignore the thermistor and use 75 degrees F as the temperature.

    When using 75 as the default temperature, the salinity will be miscalculated by the software for any water temperature other than 75 F.

    Thanks,

    Jim R.
    I saw this test in another thread and decided to give it a shot but my results are very different than everyone else.

    Before the tests the lights are as such

    Salt Level
    Low: Red

    Status
    Cell: Flashing Green
    Flow: Solid Green

    Sanitizer Output
    20%, 40%, and 60% are lit

    When I run the test it cycles through the lights from bottom to top then the Cell light is lit Green, the Cold Water Light is lit Red, and the Low light is lit Red and flickers for .5 a second. It stays like that for about 3 seconds then the Cold Water and Flow lights flash Red for approximaetly 1 second before everything goes back to the lights listed above.
    My Pool Build Thread: 21 x 40 Freeform Gunite Pool, 12" Tanning Ledge, 3.5 shallow graduating to 4.5, 8.5 deep end, 4' Waterfall which doubles as a diving ledge with 6' x 4' Grotto underneath, 670 sq. ft., 106 Linear ft., Rock Salted Concrete Deck, Pentair 520 Filter, Intelli flow 3 HP VS pump, (4) Color LED lights, Intelli-Chlor SWG, Hot Springs Vanguard Hot Tub with ACE and BT Sound System, ODK, TF100

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    Re: IC40 reading low but water tests at 3400 ppm

    Press and hold the "More" button for a few seconds until the lights scroll. Then, note what the "Cold Water" LED shows and what percentage lights are on.

    Then, quickly push the More button again and note what percentage lights light up.

    If the Cold Water LED goes solid red on the first push of the button, the system has detected a problem, usually a bad temperature sensor.

    What is your water temperature?
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    Re: IC40 reading low but water tests at 3400 ppm

    Quote Originally Posted by JamesW View Post
    Press and hold the "More" button for a few seconds until the lights scroll. Then, note what the "Cold Water" LED shows and what percentage lights are on.

    Then, quickly push the More button again and note what percentage lights light up.

    If the Cold Water LED goes solid red on the first push of the button, the system has detected a problem, usually a bad temperature sensor.

    What is your water temperature?


    Ahh, After the second push of the More button I get Low and Cold Water are both Red while Cell is Green. Then all of the sanitizer output lights flash. I guess its a bad temp sensor? Not sure the exact temperature of the water but I am guessing it is in the 60's.
    My Pool Build Thread: 21 x 40 Freeform Gunite Pool, 12" Tanning Ledge, 3.5 shallow graduating to 4.5, 8.5 deep end, 4' Waterfall which doubles as a diving ledge with 6' x 4' Grotto underneath, 670 sq. ft., 106 Linear ft., Rock Salted Concrete Deck, Pentair 520 Filter, Intelli flow 3 HP VS pump, (4) Color LED lights, Intelli-Chlor SWG, Hot Springs Vanguard Hot Tub with ACE and BT Sound System, ODK, TF100

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    IC40 reading low but water tests at 3400 ppm

    I called Pentair on This issue. They say to take the cell apart and inspect it every 3 months. They said to clean as required. First by spraying water in it to remove any scale. If scale remains they aid to axis wash 1:5 ratio for no longer than 30 minutes.

    I don't know who said to check it one a year, but that's not what they recommend. I believe it even says on the newer cells to inspect every 3 months.



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    Re: IC40 reading low but water tests at 3400 ppm

    Probably a bad temperature sensor. I would file a warranty claim.
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    Mod Squad Jimrahbe's Avatar
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    Re: IC40 reading low but water tests at 3400 ppm

    Quote Originally Posted by The dog View Post
    I called Pentair on This issue. They say to take the cell apart and inspect it every 3 months. They said to clean as required. First by spraying water in it to remove any scale. If scale remains they aid to axis wash 1:5 ratio for no longer than 30 minutes.

    I don't know who said to check it one a year, but that's not what they recommend. I believe it even says on the newer cells to inspect every 3 months.


    Sent from my iPhone using Tapatalk
    Hi Dog,

    I'm the one that said one a year inspection, but that was based upon real world experience, not Pentair's advice... I suspect Pentair is just covering there rear with the 3 month recommendation.

    It is perfectly fine with me if you want to inspect it daily, but anytime you acid wash it, you reduce the cell's life span.

    I have three of these things, and have never found more than just a minute amount of build up on the plates. It could be I'm just lucky, but I doubt it.

    And the official "Inspect your cell and clean it" is the same as an IT tech telling you to reboot your computer when you have already done that 10 times...

    Occasionally it might be the answer to the problem, but my guess it that 9 times out of 10 it does nothing to solve whatever issue you are having.

    Thanks,

    Jim R.
    Finished in 2015 - 17K Gal, IG, 20' x 25' Almost Rectangular Pool, Pebble finish, three rockport water falls. Pentair Equipment: EasyTouch 4, IC40 SWG, 3 HP VS Pump, CCP520 Cartridge Filter.
    TF100 with SpeedStir and SampleSizer, ColorQ Pro 7, Dolphin Premier Robot Cleaner, added Screen Logic 2, added small 3 person Caldera Spa.

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    IC40 reading low but water tests at 3400 ppm

    You guys can do what you want based on your experience. I was only telling you guys what they said. I've only had my ic40 running for 2 months. I haven't opened it yet

    I never said to inspect it every day.

    And back to the pc thing. A cold boot is different than a reset. And yes a cold boot can help when a reset doesn't because the memory is cleared.

    Take care JR



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    Re: IC40 reading low but water tests at 3400 ppm

    Quote Originally Posted by SoonerWing View Post
    Ahh, After the second push of the More button I get Low and Cold Water are both Red while Cell is Green. Then all of the sanitizer output lights flash. I guess its a bad temp sensor? Not sure the exact temperature of the water but I am guessing it is in the 60's.
    This is what mine did last month when I opened the pool. I replaced the temp sensor and it fixed the problem.
    30,000 Concrete/Fiberglass wall, Hayward Super Pump 1 HP Pentair Intelliflow, Hayward S244T Sand Filter, Pentair IC40 SWG, Hayward H250FDN NG Heater

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    Mod Squad Jimrahbe's Avatar
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    Re: IC40 reading low but water tests at 3400 ppm

    Quote Originally Posted by The dog View Post
    You guys can do what you want based on your experience. I was only telling you guys what they said. I've only had my ic40 running for 2 months. I haven't opened it yet

    I never said to inspect it every day.

    And back to the pc thing. A cold boot is different than a reset. And yes a cold boot can help when a reset doesn't because the memory is cleared.

    Take care JR

    Sent from my iPhone using Tapatalk
    Dog,

    Your post was fine, I was just trying to tell the other side of the story..

    Not sure what you plan to do about inspecting your cell, but if you do decide to do it every three months, please provide us with some real world feedback.
    It would be interesting to see what you find and your recommendations might help others.

    As I said, I could just be lucky,

    Thanks for posting,

    Jim R.
    Finished in 2015 - 17K Gal, IG, 20' x 25' Almost Rectangular Pool, Pebble finish, three rockport water falls. Pentair Equipment: EasyTouch 4, IC40 SWG, 3 HP VS Pump, CCP520 Cartridge Filter.
    TF100 with SpeedStir and SampleSizer, ColorQ Pro 7, Dolphin Premier Robot Cleaner, added Screen Logic 2, added small 3 person Caldera Spa.

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    IC40 reading low but water tests at 3400 ppm

    I certainly will JR. I was going to check the cell and take apart my filter at the same time. In another month.
    Like you said, different things work for different people and you need to do a little experimentation on what works best for your situation.

    Have a good one.



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    Re: IC40 reading low but water tests at 3400 ppm

    Yesterday was sunny and got up into the upper 80's and the IC40 was lit up all green and pretty. Water test this morning showed that it produced chlorine yesterday. This morning it is in the low 60's and it is not longer lit all green and pretty. I am guessing that the water temp droped over night down below the magical number. It should be another nice day today so I am interested to see if we have a repeat of yesterday. Either way my temperature sensor is on its way
    My Pool Build Thread: 21 x 40 Freeform Gunite Pool, 12" Tanning Ledge, 3.5 shallow graduating to 4.5, 8.5 deep end, 4' Waterfall which doubles as a diving ledge with 6' x 4' Grotto underneath, 670 sq. ft., 106 Linear ft., Rock Salted Concrete Deck, Pentair 520 Filter, Intelli flow 3 HP VS pump, (4) Color LED lights, Intelli-Chlor SWG, Hot Springs Vanguard Hot Tub with ACE and BT Sound System, ODK, TF100

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    Re: IC40 reading low but water tests at 3400 ppm

    As the water warms up, the salinity calculation gets more accurate because the system is using 75F as the water temperature.

    At a water temperature of 75F, the salinity should be correct.

    As the water temperature passes 75F, it will begin to read the salinity as higher than actual and might end up giving a false high salt error.

    I think that if you raised the salinity to about 3800, the cell will work.
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    Re: IC40 reading low but water tests at 3400 ppm

    I've had the recurring red low salt light before on the IC40, and I've had luck with simply getting it on a better "schedule" of testing it at the 12h interval. I cycled power on it around 11am one day, and it checked fine. Now it is probably checking at 11pm and 11am, times when the water is either still decently warm from the day or has had sun for a few hours. I suspect once June hits it will not really be a problem. Either way I think the temperature/flow sensor is probably the weakest link of these devices.
    20x40 28kgal in-ground vinyl built 2011, liner replaced 2017
    Pentair Tagelus TA60D sand filter, Pentair SuperFlow 1HP pump, Intellichlor IC40 SWG, Dolphin Active 30i
    City water, TF-100 test kit + speedstir.
    Recommended Levels | Chlorine/CYA Chart | SLAM

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    Re: IC40 reading low but water tests at 3400 ppm

    I agree as it jacks with the salinity level. In the am the pool is cold and reads low. Then at the end of the day it's warm and reads almost normal. My ic40 is about 200 +/- off from the Taylor test especially if I test in the am.



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