High CYA.

PoolNewb2020

Well-known member
May 7, 2020
297
Lathrop, CA
You need to do a diluted test for CYA, otherwise you may drain too little, fill it back up, only to find CYA still being high.
Use 50% pool water and 50% tap water. Multiply the result by two.
 

thebisch

Active member
Jun 27, 2020
39
Schenectady
Still doesn't register on the scale. Water is about 3.5 mm below 100. The distance between 100 and 9 is about 2.5 mm.

I'm going to try a third and multiply by three.

You need to do a diluted test for CYA, otherwise you may drain too little, fill it back up, only to find CYA still being high.
Use 50% pool water and 50% tap water. Multiply the result by two.
 

YippeeSkippy

Mod Squad
LifeTime Supporter
Jan 17, 2012
14,426
Evans, Georgia
I'd suggest draining by half (just to be safe and protect that liner) and then refill, let it mix with the pump on, then drain by half again and refill.
Retest the CYA and see where you are.

Maddie
 

thebisch

Active member
Jun 27, 2020
39
Schenectady
What does't look correct? At 1/2 CYA registered a little under 100, so say it was 75 - 90 or so, which makes it 140 - 180 ish. At 1/3 reading at 60 x 3 = 180 seems quiet reasonable to me considering the the visual proximate of the 1/2 test and what the strips are consistently reading (150, maybe a slightly darker shade ie: a little higher) Please correct me if i'm wrong.

Was it exactly at the 60 line or between? Did you have to stare to find the dot or did you just glance?

180ppm doesn't look correct since your 50/50 sample registered below 100, it probably over 200ppm.
 

PoolNewb2020

Well-known member
May 7, 2020
297
Lathrop, CA
What does't look correct? At 1/2 CYA registered a little under 100, so say it was 75 - 90 or so, which makes it 140 - 180 ish. At 1/3 reading at 60 x 3 = 180 seems quiet reasonable to me considering the the visual proximate of the 1/2 test and what the strips are consistently reading (150, maybe a slightly darker shade ie: a little higher) Please correct me if i'm wrong.
OP said his 50/50 was 3.5mm below the 100ppm line. 90ppm line is above the 100ppm line. If that info is correct, it indicates a reading of over 200ppm CYA
 

thebisch

Active member
Jun 27, 2020
39
Schenectady
Drained to about 17" of water remaining in the pool. Refilling as I type this. Should be at a level to turn the pump back on in a couple of hours. I'll let the pump run for a few hours and then I'll retest.
 
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thebisch

Active member
Jun 27, 2020
39
Schenectady
Pool filled back up with municipal tap water. Pump running for a few hours...

FC = 3
CC = .5
pH = 7.2
TA = 190
CH = 225
CYA = a slight hair over 80
TC = 2 or 3

What now? Probably should drain some more and refill, but I "need" to use the pool this weekend.
 
Last edited:

YippeeSkippy

Mod Squad
LifeTime Supporter
Jan 17, 2012
14,426
Evans, Georgia
80 is ideal for using a Salt Water Chlorine Generator! Wanna add one? ;)

yeah, a bit high for a manually chlorine treated pool. More fresh water exchange on your "To Do" list.

Maddie