2-year old IC60 not keeping Chlorine level up

[dcsmith]

I have only one full Summer under my belt and I expected I could follow the same pattern and levels of SWC generation this Summer. So far, that is not true and I am suspecting a problem.
In early May, the pool was a bit cloudy and the Chlorine level was down to 1.2ppm. I cranked the unit up to 100% but not much changed. I shocked the pool on 5/16/23 with 2.5 gallons of liquid Chlorine (Pinch-a-Penny). That cleared up the cloudiness. I also had the company come out and test the IC60. It tested fine with only "500 hours on it". I had the tech remove the unit so I could inspect the plates. They were clean.
The levels slowly dropped again so I shocked the pool again on 6/21/23. I have been running the generator at 80% for 7 hours a day since late Spring. In order to keep the levels up, I am having to add liquid Chlorine every few days.
If the unit tests out OK, could the power center/logic unit have a problem? I have an Intellitouch I9+3 with the power unit built in.
Needless to say I have opened a support call with Pentair and the Installing dealer.
Current chemistry:
FC:2.1
pH:7.5
TA:60
CH:260
CYA:75
Salt:3100
Borates:50

I just added 5# of baking soda to raise the TA.

 

[Texas Splash]

Really sounds like you have a chemistry problem - too much organics leading to algae. Your FC has dropped way too low. Cranking the SWG up won't do it. SWG's can't make up for the chlorine demand at this point when organics take over. Those SWG boosts are no match either. I suspect you need to perform a SLAM Process. If you have any doubts about going right into a SLAM Process, you could do an Overnight Chlorine Loss Test first, but I suspect a SLAM Process is what will be required.

 

[dcsmith]

Never any algae. It started in early May as slight cloudiness. The first Shocking (5/16/23) cleared that right up. A month later when levels were down again, but the pool was clear, I shocked it again (6/21/23).
What is wrong with my chemistry as listed? The TA was low, so I added 5# baking soda. (which will raise the pH)
I guess I need a FAS-DPD Chlorine test kit. My current kit only measures up to 8.0 ppm.

 

[Texas Splash]

What is wrong with my chemistry as listed?

Take a look at the FC/CYA Levels. Select your current CYA (round up to 80) then see what your ideal FC should be. You'll also see the absolute minimum FC level listed. Yours has fallen below that threshold more than once. The one-time shocks won't clear-up any living products in the pool. The clear water can be misleading. By performing an Overnight Chlorine Loss Test you'll know for sure if there is an algae problem.

 

[Texas Splash]

Sometimes this chart is easier to read.

 

[dcsmith]

FC yesterday was 4.4. CYA was 72. Today FC 2.1, CYA 75.

OK.
Ordering a Taylor kit. Wil do the overnight test.
When Slamming, I do not understand the "Shock Level" for Slamming. To SLAM my pool with a CYA of 70, it says "28". What is that? CYA or FC? The Taylor kit only measures up to 20 ppm.
I watched the video, but still don't understand the "Shock Level".

 

[dcsmith]

When Slamming, I do not understand the "Shock Level" for Slamming. To SLAM my pool with a CYA of 70, it says "28". What is that? CYA or FC? If CYA, do I need to LOWER my CYA before SLAMMing? The Taylor kit only measures up to 20 ppm.
I watched the video, but still don't understand the "Shock Level".

 

[reggiehammond]

SLAM levels are measured using the FAS-DPD chlorine test in both recommended test kits.
CYA is only needed to assess the proper SLAM level.

 

[Newdude]

28 is the FC level for a 70 CYA to slam. Slam needs 40% of your CYA level. You (M)aintain SLAM level for as long as it takes to rid the algae.

At first, it chews through FC and you need to dose every 2 hours or so. As the process plays out, the FC holds 4 hours, then 6, then 8. (Etc).

You can always dose ahead of schedule for that part of the SLAM and buy yourself the next block of time away. It's pretty easy to work around. Many have started it on their first day off, planning to be around. By day 2 they can get out for 4 to 6 hours at a time and on day 3 it's holding long enough to go to work. (Dosing before and after).

The fas/dpd FC test in the kit was verified to 50ppm. Human error became too much at that point (making 100 perfect drops) so the tester stopped. The kit was capable of plenty more. Lol.

Algae grows exponentially when it's warm out. Many times the pool owner is barely keeping at bay but those last couple of growth cycles are the difference between a mild bloom with clear water, and a full blown swamp. Frequent testing sets off early red flags so you can step in before it becomes miserable to fight. No matter how bad it is, you always want to retain the leg up in the battle, and also no matter how bad it is, the more effort you put in maintaining the FC and brushing, the quicker it goes.

 

[dcsmith]

SLAM levels are measured using the FAS-DPD chlorine test in both recommended test kits.
CYA is only needed to assess the proper SLAM level.

What kit will measure FC UP TO 50? The Taylor kit only measures up to 20. At chlorine levels at or above 28, won’t that damage pool equipment?

 

[Newdude]

The Taylor kit only measures up to 20.

For the fas/dpd test you add drops and can add as many drops as you need. At high levels, human error comes into play, not the test being incapable. Taylor may only certify it to 20, and if so, it's because the industry never wants you above 4ppm, so that's insanely high to them.

Which kit did you order ?

At chlorine levels at or above 28, won’t that damage pool equipment?

Chlorine is bound by the CYA. With more CYA you need more FC to sanitize at the same level. Any line on this chart is equal for sanitizing. And to the right side, SLAM, is less harsh than tap water with 0 CYA and up to 4 ppm FC.




Check out
FC/CYA Levels
Pool Care Basics

 

[dcsmith]

Taylor K-1515-A

 

[mknauss]

Using a 10 ml water sample, each drop of reagent to clear is 0.5 ppm FC. That is sufficiently accurate to 50 ppm FC.

 

[reggiehammond]

At chlorine levels at or above 28, won’t that damage pool equipment?

Here's the law... FC/CYA Levels

 

[dcsmith]

Using a 10 ml water sample, each drop of reagent to clear is 0.5 ppm FC. That is sufficiently accurate to 50 ppm FC.

OK. Test kit due this Sunday.

First off, my pool water is clear and has been since mid-May. Even at that it was only slightly cloudy. The first shock of 2.5 gallons 10.5% liquid Chlorine cleared that up.

Using the "Pool Math" calculator, I need to add 5 gallons of 10.5% liquid Chlorine to slightly exceed the necessary 28ppm of Chlorine. I am concerned that this level of Chlorine will damage pool equipment (pumps, heaters, filters, etc.).
Today's measurements (after adding 1/2 gallon of liquid Chlorine yesterday afternoon):

FC:5.7
CC:5.8
CYA:75

My CC is only .1 greater than FC. What am I missing?

 

[dcsmith]

Here's the law... FC/CYA Levels

How does that answer my question?

 

[reggiehammond]

Now I'm confused on what we're talking about...

The science behind how CYA buffers FC levels is the basis of the TFP method. You will not damage your equipment during SLAM when using proper test kit data. Just won't happen.

 

[dcsmith]

Now I'm confused on what we're talking about...

The science behind how CYA buffers FC levels is the basis of the TFP method. You will not damage your equipment during SLAM when using proper test kit data. Just won't happen.

I am concerned about the very high FC levels during the SLAM process. I have read that most pool equipment prefers 10ppm or less (from recollection). I have not read anything in this forum that states SLAM levels will NOT hurt pool equipment.

 

[Newdude]

I am concerned about the very high FC levels during the SLAM process

Yes. We hear you. It's unfounded. SLAM is less harsh than tap water with 0 CYA and up to 4 ppm FC. Have a quick read:
FC/CYA Levels

I have read that most pool equipment prefers 10ppm or less (from recollection)

The industry doesn't recognize the science of how CYA reacts with FC. They have their head stuck in the sand following government sanitation regulations which haven't been updated since the 80s.

. I have not read anything in this forum that states SLAM levels will NOT hurt pool equipment.

Forget your equipment. SLAM is safe for *you* to be in, and you're far more delicate than PVC and such.

 

[Mdragger88]

I am concerned about the very high FC levels during the SLAM process. I have read that most pool equipment prefers 10ppm or less (from recollection). I have not read anything in this forum that states SLAM levels will NOT hurt pool equipment.

CYA Chlorine Relationship - Further Reading

www.troublefreepool.com

Synopsis: “a pool at SLAM level has only 1/5th the active chlorine (HOCl) as a pool that is within CDC guidance for safe and ideal.”
Slam level fc as per the chart will not damage surfaces, equipment, or swimmers.

Just so you’re understanding- your one time “shocks” may have kept algae at bay but likely didn’t eradicate it. Unless you did an
Overnight Chlorine Loss Test afterwards to prove this you can’t be sure.

About your ic60-
Here’s what 7 hrs/day @ 80% looks like in your pool

The average fc loss in an algae free residential pool can be around 5ppm/day in the peak of summer. Especially in Florida.
Around 2ppm in the spring. You must adjust your % & run time according to the season & conditions. It’s not set it & forget it.
Also, riding minimum is not recommended - it leaves no wiggle room for a high uv/high bather load day or whatever else occurs.
Going forward (after completing the slam process if necessary)
You want to maintain upper Target range fc so you know you’re covered.

FC/CYA Levels