Which issue should I address first?

lastevns · Feb 19, 2025

Hi all,
I have been out of the country for work and haven't had the chance to check water in awhile. While I was gone, we had rain for a about 4 days. I did my numbers this morning and have some troubling results. I'm wondering if experts, here, can tell me which troublesome number to address first:

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My readings (I think these might come up in my signature):
Free chlorine: 8PPM (Just added 30 .oz of liquid chlorine/10% last night)
Combined chlorine: .7. The TF100 test didn't quite clear at one drop of R-0871 (though it was nearly clear). So I put one more drop.
Total chlorine: 8.7
PH: 7.8
TA: 100
CH: NA (AGP)
CYA: ~10 to 20

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I assume the CYA is the biggest issue. I have a solar blanket on the pool now but plan to clean the debris from pool bottom and, once I have numbers at acceptable levels, cover the pool with the solid cover.

Please let me know if I am correct in addressing the debris and CYA first and if I should retest chlorine stability following CYA. It appears I need to add 23 .oz of CYA (I'm using dry powder). How long should I run the pump - until dissolved or for a fixed time?
(Adding note: it's between mid 60s as a daily high to high 30s as a low, here, right now).

Thanks!

Newdude · Feb 19, 2025

Welcome back !!! :wave:

Get 15 ppms worth of CYA soaking in a sock or such, carrot on a stick like. Some hours later or even tomorrow it'll squish right out. Brush well after.

How's the water look ? If TFP clear,
Overnight Chlorine Loss Test to make sure nothing is brewing.

If any algae is visible anywhere or the water is green, head straight to SLAM Process

lastevns · Feb 19, 2025

Newdude said:
How's the water look ? If TFP clear,
Overnight Chlorine Loss Test to make sure nothing is brewing.

I was shocked to see that it's not at all green (though I may have to take off the solar cover in light to really examine well). But, the water is usually crystal clear and I would say it's a tiny bit murky now. That could be the debris that fell from trees (above pool) during rains.

I thought I saw something about overnight chlorine loss tests. I will do that. And, yeah, I thought I might have to SLAM the pool so I have printed out the instructions and got up before sunlight this morning to test. But, it's possible I MIGHT not need to. Should the pump run the entire time I'm trying to dissolve the CYA? The water is SUPER cold so I am not certain it will dissolve without my help (like squeezing the sock regularly). But, should I run the pump that entire time?

Newdude · Feb 19, 2025

lastevns said:
I would say it's a tiny bit murky now

The overnight test will let you know if it's organic / algae or yard crud that just needs alot of filtering.

lastevns said:
Should the pump run the entire time I'm trying to dissolve the CYA?

Yes. Hang the sock in front of a return and let it soak with water movement.

lastevns said:
like squeezing the sock regularly

When it's warm it dissolves way faster but I try to not micromanage it before it's ready. If it doesn't squish out in 30 mins, give it a few hours. If it's still stubborn, let it be until tomorrow.

Count it as added as soon as it's soaking for your FC levels (if FC dips)