SWG not making chlorine and can't figure it out

PooolGuyy

Member
Mar 18, 2019
8
Southeast US
Hi guys! My pool is about two years old and still under warranty for a couple more months and my Pentair SWG wasn't making chlorine, so Pentair had someone come out and take a look at it. The repair guy first put a new flow switch on, and I gave it a couple days and it still didnt produce enough chlorine, so he came out again and put a new cell in. After about 2-3 days of having it on 24 hrs a day at 100 percent chlorine output, the chlorine level is in the "okay range" but on the low end. So it's making some chlorine now, but correct me if I'm wrong, but shouldn't leaving it on for almost 3 days at 100 percent give me a very high chlorine reading? I tested it very early in the morning also. I've attached a picture of the test strip. Test strips work and haven't expired. Also the free chlorine is very low and I can't get that raised using the swg. If the problem isn't the flow switch or the cell, what could it be? Any help would be appreciated!!

Thanks!!
 

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Donldson

TFP Expert
LifeTime Supporter
Jun 12, 2009
4,620
NW Ohio
You said in a post last year that you got a Taylor k-2006c. Why are you using test strips?

Test strips are inaccurate and unreliable, we can not use them to diagnose a problem.
 
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PieterS

Active member
Jul 1, 2020
34
Minneapolis, MN
I would assume that a repair guy worth his mettle would have a way of checking whether a brand-new cell installed is functioning correctly - so I'll assume it is.

You'll probably have folks chime in that test strips are notoriously inaccurate - be that as it may, if you haven't changed how you're testing, I'm more tempted to think that your SWG is actually generating chlorine, but something is consuming it in your water (early algae bloom?)

If you could add the model/brand of your SWG and all other pool equipment to your signature, that'll be a good start to go with
 
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thetekgeek

Bronze Supporter
Jun 8, 2018
258
Nebraska
In order to help you, there are a few things we need to know and those things cannot come from a pool store or a test strip. You need to be able to reliably test your water and provide accurate readings in order to get sound guidance. Please look into a quality test kit, there are two recommended by this site. Taylor K2006C or the TF100. I have the TF100.

Now to your immediate problem. If you have adequate salt in the water, and there are no errors being displayed on your cell, it is very likely that the cell is producing chlorine. Have you been running it 24/7 at 100% output for the past three days? I have a sneaky suspicion that when the original flow switch failed and the cell stopped producing chlorine, something began to grow in your water. You may not be able to see it yet, but I suspect it is there. SWG's produce chlorine slowly and if you are on the edge of an algae bloom, the algae is probably consuming it just about as fast as the cell is producing it.

Get an accurate test kit (including a salt test) and post those results. We can take it from there.
 
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SouthVirginiaPool

Silver Supporter
Apr 26, 2020
104
Chesapeake, Virginia
I would second what PieterS said. It is either an issue with chlorine PRODUCTION or with chlorine CONSUMPTION. Using the Taylor kits are the most reliable way to diagnose what is going on - I would post a complete panel to include FC, CC, CYA. etc. Test strips are not reliable enough especially when you are tyring to get to the bottom of a problem.
 
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Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
23,932
San Dimas, CA (LA County)
A few thoughts, not especially original
1) Test strips are terrible. If chlorine is super high, they'll eve bleach put and read falsely low.
2) While you weren't producing you may have developed algae
3) Your test strip photo is cropped where we can't see the CYA spot. Maybe you are producing and you don't have algae but the sun is stealing it all due to low CYA?

As always, the place to start diagnostics is with reliable test results.
 
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PooolGuyy

Member
Mar 18, 2019
8
Southeast US
Thanks for all the replies!!

I'm currently away from the pool so I can't use my Taylor kit right this second, but the test strips I use have always been pretty accurate when compared to my Taylor kit and I've always kept my pool balanced really well using them. But I will use my Taylor kit when I'm home.

As for equipment, I have a Pentair Intellichlor model IC15. All the readings on it indicate good cell etc. But when it originally stopped working, all the light readings indicated good cell etc, so I don't know if that can be trusted.

The cya is low, but running for 3 days (24hrs a day) at 100% output and testing early in the morning like I did before the sun is out, should give me an extremely high chlorine reading. My pool is less than 10,000 gallons.

A couple mentioned the beginning of an algae bloom, which could be and I don't see it yet, but I've had algae blooms that I could see before and I would turn up the chlorine output on the Pentair and it would take care of the problem quickly.

So to sum up, my test strips are usually right, but I will check with my kit. Don't think it's the beginning of an algae bloom, but I've had them before and turned up chlorine output and that solved them quickly, so that doesn't seem like this. Also, I use algaecide 60. Cya is low, but running constantly and testing before the sun comes out should give me a very high reading for such a small pool.

Thanks for all the help guys!