High CYA and green pool

[elglide]

Have an AG pool, trouble-free for over a year, but started having issues about a month ago when the pool turned green.

We've been using tablets with an occasional shock. When we shocked it this time, it felt like the problem got worse. I read through the forums and other online places, and I think the issue might be high CYA. I'm feeling pretty lost, so I hope you all can throw me some good advice.

This weekend I drained about half the pool and added fresh water (we are on a well with a water softener). Retested my levels tonight because the water is still green. FC is 16.0 (!), pH is 7.2, TA is 80, CH is 30, CYA is over 100.

At this point, I'm thinking using tablets has caught up to us and the CYA is blocking the chlorine from doing its job. Which means I'll have to do another partial drain and fill and retest.

What say you? Am I on the right track?

 

[mknauss]

Welcome to the forum!
Do an extended CYA test. See CYA - Cyanuric Acid Test - Trouble Free Pool
You can drain to the point you have 18" of water in the pool and then refill. Let us know what the extended CYA test result is.
I suggest you read ABC's of Pool Water Chemistry.

 

[elglide]

Will do - I'm off to drain the pool and will post an update.

 

[PetPsychic]

When I created my first account, I must have entered the wrong email and couldn't recover it. So, I created this new account. All the information is still the same - it's still me.

So, this is the update. I drained about half the pool, refilled, and retested. These are the results:
FC - 6.0
pH - 7.2
TA - 90
CH - 10
CYA - 60

Pool is no longer green, but it is still a bit cloudy. Because we are on a well, I'm kind of reluctant to drain again. I'm thinking we can lower the CYA through swimming, backwashing, and vacuuming. We'll stop with the tablets for now and just use liquid bleach.

Any other recommendations?

 

[mknauss]

When I created my first account, I must have entered the wrong email and couldn't recover it. So, I created this new account. All the information is still the same - it's still me.

@Leebo -- Please see if you can resurrect the original account.

 

[Rancho Cost-a-Lotta]

Pool is no longer green, but it is still a bit cloudy. Because we are on a well, I'm kind of reluctant to drain again. I'm thinking we can lower the CYA through swimming, backwashing, and vacuuming. We'll stop with the tablets for now and just use liquid bleach.

CYA of 60 is no problem. Just maintain FC per the CYA/Chlorine Chart.

The Free Chlorine and Cyanuric Acid Relationship

Managing your cyanuric acid and Free Chlorine levels is key to stabilizing your pool. Learn how these two items affect each other.

www.troublefreepool.com

 

[Rancho Cost-a-Lotta]

Any other recommendations?

Do an overnight chlorine loss test to rule out algae.

Perform the Overnight FC Loss Test (OCLT)

The Overnight Chlorine Loss Test tells if the SLAM is finished or if you need to start a SLAM. This article says how to do the OCLT.

www.troublefreepool.com

 

[PetPsychic]

Thank you for all of your support! I had to send followup.

Do an extended CYA test. See CYA - Cyanuric Acid Test - Trouble Free Pool
You can drain to the point you have 18" of water in the pool and then refill. Let us know what the extended CYA test result is.
I suggest you read ABC's of Pool Water Chemistry.

You got me started in the right direction. It took two drain-n-fills to get the CYA down to an okay level.

Do an overnight chlorine loss test to rule out algae.

I did the overnight chlorine loss, and it didn't really indicate I needed a SLAM. However, the water was cloudy, and the CC was about 0.5 ppm, so I I gave it a try. It totally worked! Here's some pics of the process.

This is when I first started the partial drain & fill:


And after the SLAM:


The process was complicated a bit by some mechanical failure - discovered that one of the pump capacitors was bad and the thermo overload shut down the pump on day two of the SLAM. Thank you, Amazon, for Prime shipping. Overall, it took four days to finish.

I'll keep viewing articles and following the maintenance schedule.

Again, thank you for your quick and helpful advice. You all rawk!

 

[Rancho Cost-a-Lotta]

Great outcome.

Enjoy the pool!

 

[mknauss]

Great Job!

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[PetPsychic]

Great Job!

We are glad you have found our information helpful. Please, if you can, consider making a donation to TFP.

We are staffed by volunteers and are registered as an IRS 501 (c) (3) charity and donations are what keeps the forum operating without advertisements.

Support TFP!

Easy enough - did just that!