FC/CYA/SWG Recs

soccerballbmw

Bronze Supporter
Jan 18, 2024
47
Saint augustine, Florida
Pool Size
11500
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Hi all. I've had a hard time the last couple of weeks keeping my FC from dropping to 1 on the daily. I only recently got a pool (March...ish) and have had an easy time with it so far. I never had to add any chlorine (after the pool builder initial set up), keeping my SWG set at 50% and CYA at 60/70, I had no trouble keeping FC between 5-7. Starting in June, I've been constantly adding chlorine, using the PoolMath App's recs. This may be perfectly normal, but I just haven't had a pool before to know if it is. I can only assume being in florida with an extreme UV and no cover/shade reduces the FC considerably compared to other environments so i'm asking for recommendations on where to keep my levels based on those factors. Should I look for a CYA range of 80-90 instead? I've had the SWG at 80% for 3 weeks (9am - 1030pm) and according to my logs i've added 2 quarts of 10% chlorinating liquid 14 days ago, 52 oz 9days ago, 45 oz 5 days ago, 36 oz 3 days ago, and 70 oz an hour ago (after i was showing 1.5 FC). My CYA remains either 60 or 70, its so hard to tell, the CYA test is too subjective for me, i feel like i always see the dot... but reading through the forums here, I'm confidently in the 60/70 range, but if there is a better way to test than the dot, please let me know. Thanks in advance for your advice!
 
If your FC has been falling to about 1 ppm on numerous occasions, I suspect you have an algae issue brewing. Before you do anything else with CYA, I would recommend doing an Overnight Chlorine Loss Test first. Then we can go from there.
 
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Thanks for the reply! I test the FC just about every day and i haven't had it below 1 or probably 1.5 yet. I just added that 70 oz of 10% chlorinating liquid, i'll test to see where that gets me in an hour or so and more to get to the range you suggested if still not there.
 
I test the FC just about every day and i haven't had it below 1 or probably 1.5 yet.
Yes, but see that's too low already (algae). Remember to always refer to the FC/CYA Levels. See the chart below for a good visualization. Those "MIN" numbers are just that - bare-bones low. That's flirting with algae. For us salt pools, the FC should always be around that 5-7 range.

full
 
Yes, but see that's too low already (algae). Remember to always refer to the FC/CYA Levels. See the chart below for a good visualization. Those "MIN" numbers are just that - bare-bones low. That's flirting with algae. For us salt pools, the FC should always be around that 5-7 range.

full
Ah Got it! Thank you! I'll make the adjustments and do the test you mentioned. I see in the article it mentions to turn off the SWG for the night. Does it matter whether or not the pump runs?
 
Does it matter whether or not the pump runs?
While the instructions do give the option to turn the pump off, I personally like to leave it running. Low speed is fine, but that way you don't have to worry about turning it on again and when you can take the next sample in the morning.
 
Haha yep! I always thought it would be obvious (visually) to have algae/contaminant in the pool as it looks clear to me. Always learning thanks to this forum and I have many more questions to come after this process haha. Figuring out the best pump speeds for one, not sure I want to blindly trust the pool company on that as I have been doing.
 

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Sounds like your swcg was helping keep it under control but algae would have eventually won.
That’s the great thing about testing accurately your self - you can catch problems before the pool goes full Hulk!
Hopefully you’ve caught it early & the
SLAM Process won’t take terribly long!
Follow the article to the T & leave no stone unturned whilst slamming.
SLAM ON 😎
 
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I do - some don’t but my pool is too big to manually vac without getting in so I use my bot 99% of the time.
it stays in the pool all the time since i have it run on a schedule daily.
During slam I do remove it after its run & rinse it off.
 
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welp. i didn't consider how much reagant i would be using and none of the stores here carry r-0871. I have enough for maybe two tests. Amazon sending a new bottle tomorrow. I guess i'll just try to maintain the best i can with the regular FAS test and start anew when the reagent comes lol
 
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Also- if you’re logging in poolmath you can turn on sharing and we can see your logs - this is helpful for us to see the whole picture.
Hit the ⚙️ in the top right corner
Then scroll down
IMG_0511.jpeg
 
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Also- if you’re logging in poolmath you can turn on sharing and we can see your logs - this is helpful for us to see the whole picture.
Hit the ⚙️ in the top right corner
Then scroll down
View attachment 589344
I always use the app, but don’t always keep the log. I believe I have for this process tho.

 
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