FC zero in SWG pool

johnfam21

Well-known member
Apr 11, 2023
64
Wyomissing, PA
Pool Size
32000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Hayward Aqua Rite (T-15)
Hi,

I tested my pool today with my kit. See results below. To my surprise, the FC was zero. Surprising because it was actually high for a bit. I used the Pool Math app and did what it suggested and turned my SWG to super chlorinate for 18 hours. Should I just trust the SWG to bring chlorine up or also add chemicals?
I am sort of kicking myself because I had a group of my son’s friends swimming earlier. SMH
------------------------------------------
Test Results 07-21-2024 @ 10:46 AM
------------------------------------------
Free Chlorine: 0.0
Combined Chlorine: 0.5
pH: 7.8
Total Alkalinity: 60
Calcium Hardness: 500
CYA: 60
Salt: 3400
Temperature: 83°F
CSI: 0.00
 
Pool is way to big to raise your FC level that quickly. I would add some LC quick. Sometimes when you're low you can do that but zero is waaaay too low with CYA 60. Get it up there pronto. Can you give us some more background? How long has it been running? What test kit? Your test logs show mostly very high FC but also not many readings. I can guess or speculate some but would help to have some more background and please fill in your signature. Here's how. In the meantime just get the FC up to a few ppm above target. Then you can adjust. Please add your swg model number and we can give you initial settings. You should be running in a range above target and down to target within a week or so and never drop to min.

I hope this helps.

Chris
 
Thank you
Pool is way to big to raise your FC level that quickly. I would add some LC quick. Sometimes when you're low you can do that but zero is waaaay too low with CYA 60. Get it up there pronto. Can you give us some more background? How long has it been running? What test kit? Your test logs show mostly very high FC but also not many readings. I can guess or speculate some but would help to have some more background and please fill in your signature. Here's how. In the meantime just get the FC up to a few ppm above target. Then you can adjust. Please add your swg model number and we can give you initial settings. You should be running in a range above target and down to target within a week or so and never drop to min.

I hope this helps.

Chris
Thank you. I just started to run the pump at that setting today earlier this morning. I am using the TFP test kit.
 
Pool is way to big to raise your FC level that quickly. I would add some LC quick. Sometimes when you're low you can do that but zero is waaaay too low with CYA 60. Get it up there pronto. Can you give us some more background? How long has it been running? What test kit? Your test logs show mostly very high FC but also not many readings. I can guess or speculate some but would help to have some more background and please fill in your signature. Here's how. In the meantime just get the FC up to a few ppm above target. Then you can adjust. Please add your swg model number and we can give you initial settings. You should be running in a range above target and down to target within a week or so and never drop to min.

I hope this helps.

Chris
Also, I have a Hayward Turbocell Tcells340
 
John,

You have a 40K cell in a 33K pool, so that is on the small size. We recommend a cell that is rated for at least 2 x the volume of the pool.

Not a killer in your location, but still small..

How many hours do you run your cell each day and at what output%?

Thanks,

Jim R.
 
John,

You have a 40K cell in a 33K pool, so that is on the small size. We recommend a cell that is rated for at least 2 x the volume of the pool.

Not a killer in your location, but still small..

How many hours do you run your cell each day and at what output%?

Thanks,

Jim R.
I run my pump from 9-3 everyday with SWG at 50%.
 
John,

You have a 40K cell in a 33K pool, so that is on the small size. We recommend a cell that is rated for at least 2 x the volume of the pool.

Not a killer in your location, but still small..

How many hours do you run your cell each day and at what output%?

Thanks,

Jim R.
What SWG would you recommend for my size pool? Does Hayward make generators with over 40k gallons? Thanks
 

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John,

I am confused... :scratch:

Your SWCG produces about 5 ppm of FC in your pool when running 24 hours at 100% or about .2 ppm per hour.

If you run your pump from 9 am until 3 pm that is 6 hours or only 1.25 ppm per day.. And since your output is 50% then you are only adding .625ppm per day..

Most pools use 2 to 4 ppm of FC per day, so I don't understand how you are keeping your FC up at all..

I must have screwed up something..... not sure what..

Do you routinely shock your pool, or add liquid chlorine, or use tabs or ???

Thanks,

Jim R.
 
John,

**** EDIT my cut and pasting errors made it to where this didn't make sense. Now fixed****
Now we're starting to get more information the picture is becoming clearer. TFP methods are pretty simple and very effective. They rely on simple tests so we start with accurate information then we use simple tools to figure out what to do that results in a perfect pool at the cheapest cost. Here's what we know:
  • Pool size
  • swg brand, model - this tells us you are supposed to make 5.3 ppm in 24 hrs at max conditions
  • Your logs indicate you've had way over 5 ppm but you don't have logs frequently enough to really diagnose. The FC levels indicate you must be doing something in addition to run your swg that raises the FC.
Here's what we don't know:
  • What are your settings
  • Daily test results for a few days
  • What else are you adding?
  • How old is your swg?
  • How are you testing salt?
If it were my pool here's what I'd do:
  • Raise FC to 9 ppm with LC (see chart clip below)
  • Turn swg on at max and run 24 hr
  • Check FC, CC, pH
  • Report the numbers here
  • Fill out signature so we don't have to read through all the posts to find out basic information about your pool. Our volunteer experts only have so much time available. This gets you answers your questions quicker and helps them be productive with their volunteer time. It's simple, here's how.
  • You'll get advice on the next step quickly right here.
Your cell is too small for your pool but may work for a year or so, especially at your location up north with relatively short season as @Jimrahbe mentioned. Cells degrade over time so if your cell barely keeps up to start with it will degrade to the point you need to add LC which sort of negates the benefit of swg. So we recommend 2x size. I only know of two that make the enough. Circupool and Pentair as @PoolStored mentioned above. Eventually, when yours doesn't produce enough I would switch to one of them. Automation systems figure in to this decision a little but in my opinion it's not very leveraging. If you buy the same brand swg as your automation you can control % power and run time. In your case there's not an swg available that will make enough FC so it doesn't really matter. Yes, you can run two but that's unnecessarily complicated and expensive. You don't need to change % power that often. You should be able to get by with max power and adjust run time only unless You and you can do this until you start needing more FC than your unit makes. Then buy one of the 60 size units and set it up with run time control only. You can use your existing system to do this if you have a spare relay and most installations do. You'll have to set % power manually but that isn't usually required more than every year or so. I'm in a similar situation where I need the largest size. I bought a Circupool RS 60 because it was the best price/# chlorine at the time. I'm ambivalent on brand since my automation doesn't control % power on either and both of these have good warranty, reputation here.

I hope this is helpful.

Chris

1721645093104.png
 
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John,

I am confused... :scratch:

Your SWCG produces about 5 ppm of FC in your pool when running 24 hours at 100% or about .2 ppm per hour.

If you run your pump from 9 am until 3 pm that is 6 hours or only 1.25 ppm per day.. And since your output is 50% then you are only adding .625ppm per day..

Most pools use 2 to 4 ppm of FC per day, so I don't understand how you are keeping your FC up at all..

I must have screwed up something..... not sure what..

Do you routinely shock your pool, or add liquid chlorine, or use tabs or ???

Thanks,

Jim R.
That is great information I did not know.

Obviously, I am new to this since we just built our pool and this is our first season. I am assuming when our pool guy opened the pool he shocked it. We are only using him to open/close the pool.

You didn’t miss anything. As background, we started with our chlorine very high so didn’t need to do much with it. It was as high as above 20 ppm. I have never placed any chlorine in the pool until last night.

Thanks Jim.
 
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I have Hayward system using the Omnilogic platform.
You have the largest cell that is compatible with the Omnilogic platform.

Pentair and Circupool make 60K cells. I don't believe that either are compatible with Omnilogic.

You can use two cells in parallel, but a pool automation system can only control one SWG. SWG Multiple Cells - Further Reading

Let's see if I missed something or I'm wrong. @Jimrahbe, @ajw22 , @JamesW
 
All,

I really appreciate everyone’s input. I will apply each one of them and circle back here later. Obviously, I am new to this so still learning about each detail of caring for my own pool.

Thank you for your patience and guidance.

John
 

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