Help understanding test results and whether to turn on my swg

Alexanders

Member
Apr 19, 2021
23
Mid Missouri
Pool Size
4500
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Intex Krystal Clear
Hi, I have an 18 x 9 intex pool running a 1200 gph sand filter and intex swg. I filled the pool earlier this week for the first time. The salt finally dissolved yesterday and i turned on my SWG. My free chlorine got up to 4 yesterday so I turned it off. I'm trying to figure out if I should turn it back on today. My pool is in a wooded backyard and gets very little sun (to the extent that matters for chlorine breakdown). Pool looks clear, but has sediment on the bottom. I have a vacuum on order. Here are my results this morning:

FC: 3
PH: 7.2
Alkalinity: 120
Salt: 2000
CYA: 30? I think? That little black dot does not disappear completely, but it is pretty obscured at 30. The container does not take more than that. I have had a lot of trouble getting cya to dissolve. I tried the sock method (and squeezing it) for three days and it did not dissolve. I then put it in a bucket and mostly dissolved it and poured it in.

Here are my questions:

Should I turn on my swg? The manual says to run for 6 hours a day but my FC is at target.

Should I add more salt? Pool math says yes, but again, I seem to have plenty of FC (it was as high as 4 yesterday)

Should I add CYA? if yes, please tell me how to dissolve it other than the sock method. I am thinking warm water in a bucket?

What (if anything) should I do about the alkalinity?

Thank you so very much!
 
CYA: 30? I think? That little black dot does not disappear completely, but it is pretty obscured at 30. The container does not take more than that. I have had a lot of trouble getting cya to dissolve. I tried the sock method (and squeezing it) for three days and it did not dissolve. I then put it in a bucket and mostly dissolved it and poured it in.
Check out this link for more help on the CYA test, it's the most difficult test IMO: CYA - Cyanuric Acid Test - Trouble Free Pool

Either way, 30 is too low for a SWCG pool, and it sounds like it could be lower. When you use a sock is it a pretty thin sock? I have a thick sock I use and if I squeeze it a lot it'll still take about 2 days for it to dissolve in my pool. A lot of people use pantyhose since they are so thin.

Should I turn on my swg? The manual says to run for 6 hours a day but my FC is at target.
You need to run the SWCG enough for it to keep your FC in the target range, the manual is probably just guessing based on an average sized pool, under average conditions, etc.
Should I add more salt? Pool math says yes, but again, I seem to have plenty of FC (it was as high as 4 yesterday)
What does the manual for the SWCG say to target? Salt cells usually create FC when the salt is within a range, but you want to just follow the manual.
What (if anything) should I do about the alkalinity?
I wouldn't worry about that right now. Get everything else dialed in and then you can mess with pH/TA.
 
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I would raise cya up to 80 ppm. I would also run the swg and see what it says the salt level is. More than likely it is too low so you will need to raise it.
 
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Check out this link for more help on the CYA test, it's the most difficult test IMO: CYA - Cyanuric Acid Test - Trouble Free Pool
Either way, 30 is too low for a SWCG pool, and it sounds like it could be lower. When you use a sock is it a pretty thin sock? I have a thick sock I use and if I squeeze it a lot it'll still take about 2 days for it to dissolve in my pool. A lot of people use pantyhose since they are so thin.


You need to run the SWCG enough for it to keep your FC in the target range, the manual is probably just guessing based on an average sized pool, under average conditions, etc.

What does the manual for the SWCG say to target? Salt cells usually create FC when the salt is within a range, but you want to just follow the manual.

I wouldn't worry about that right now. Get everything else dialed in and then you can mess with pH/TA.

Thank you. I read the link re CYA. The pictures are helpful. My test is farther than the mid-test but not as far as the end test. That filled the tube all the way (for a measurement of 30, so my guess is that it is more than zero but less than 20. I am going to try panty hose; I used a thick sock before.

The manual says the salt level should be 2500-3500, ideal = 3000 and run for 6 hours a day for my pool size (4500 gallons). it has been 14 hours since my last FC test (=3) and I just tested it again. FC =2.5. It has been raining all day and nobody has gone swimming. I turned on the saltwater pump. It is working (I can smell the chlorine!) and the low salt indicator is not on. I have it set for four hours, but worry I will have very high chlorine by then. Thoughts?

Thanks!
 
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I would raise cya up to 80 ppm. I would also run the swg and see what it says the salt level is. More than likely it is too low so you will need to raise it.
Ok! Turned it on and no low salt warning. Also, strong chlorine smell by return. Seems to be working! Any thoughts on how long to run it. Fourteen hours since my morning FC and FC has gone done .5 from 3 to 2.5. (It is rainy here and nobody has been swimming today) Should I continue to monitor FC every hour or so to determine when to shut it off?
 

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It's been three days. I've been running my SWG five hours a day and I added cya. Currently my FC is 4.5, my CC is 0, and my CYA is 55. I still have some CYA in the sock, though, so I am not going to add more until that dissolves. It has been raining and the pool has been covered for all three days.

Is 4.5 too high for FC? Can we swim? Should I run my SWG for 4 hours instead of 5?

THANKS!
 
For a CYA of 60ppm, the target FC is 5 ppm. So no, it is not too high. I would target at least 5, preferably 6 ppm FC.

You can swim in a pool when FC is between minimum and SLAM level. For 60 ppm, that is 3 ppm to 24 ppm FC.
 
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