CYA not really dropping

[Tonka Tuff]

Hi all,

My CYA was 100 last week (When I say 100, I lost sight of the dot right when the water line hit 100 so I'm somewhat confident that it is truly 100 and not higher than that.

I dumped about 1 1/2 - 2 feet of my pool water and refilled using garden hoses.

Checked CYA today and same thing, 100 (dot disappearing right as the water hit 100)

Either I am wrong an my CYA is over 100 or something funky is going on. I figured dropping that much water out would at least get me to around 90 or even 80.

Any ideas?


FC: 25
CC: 0
TC: 25
PH: 7.8
TA: Fault due to high chlorine
CYA: 100

 

[Texas Splash]

Yeah, I suspect the CYA was a bit over 100 which was throwing you off a bit. You might want to try the dilution test method to be sure:

CYA Dilution Testing:
Add pool water to bottom of sticker.
Add tap water to top of sticker.
Shake.
Pour out half so mixture is to bottom of sticker.
Add reagent to top of sticker.
Shake.
Test outside with back to sun and tube at waist level.
Pour back and forth a few times to see if you get the same result.
Double the result.

 

[surfingcrna]

We just bought a home with a pool, and the CYA was 100. After reading many threads here, and researching much on the web, we decided to drain the pool to dilute it. The pool math calculator was right on as I needed to drain half the water in my pool. Drained and replaced from the hose and finished at 52.

Did you enter you pool information into the calculator to give you the correct amount to drain? I do remember a comment of someone suggesting to test the CYA in the hose water if the CYA didn't drop, not sure why CYA would be in the water, but I had no issues in Orlando. Maybe it's over 100 like he said.

 

[YippeeSkippy]

There is no CYA in tap water. Tonka Tuff's CYA most likely was far above 100ppm, and the 1.5'-2' water exchange in an 18,000 gallon pool barely touched it

I would for sure do another cya test using the dilution method (1/2 tap water + 1/2 pool water, doubling result) to determine just how high it truly is.

 

[needsajet]

Not relevant to your question, but just a heads-up that it's pH that will be high and incorrect when FC is above 10.

 

[Tonka Tuff]

Thanks all, I'll do a dilution test in the AM. Just got finished setting up a surround sound system and hanging a TV for the wife for the 4th. I'm done for the day lol.

And yes, Needsajet, I've got a few wonkie readings from the high FC. If I can just get the CYA to drop then I can start burning off some of the FC and get back to normal.

Looks like I'll need to do another drain and refill.