# High CYA.

#### thebisch

##### Active member
I don't know? You tell me? Lower than two feet, meaning 2 feet of water remaining in the pool, or two feet down from full?

Okie doke....how much are you planning to drain and replace to lower that CYA??

Don't go lower than about 2' or you risk the liner shifting.

Maddie

#### PoolNewb2020

##### Well-known member
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
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.

I mean 3/4.

#### thebisch

##### Active member
3/4 tap water. Measures at 60. 60 x 3 = 180.

#### YippeeSkippy

Mod Squad
LifeTime Supporter
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

#### PoolNewb2020

##### Well-known member
3/4 tap water. Measures at 60. 60 x 3 = 180.
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.

#### thebisch

##### Active member
Exactly at the 60 line. Stare, with one eye.

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.

#### thebisch

##### Active member
Being pumped out as we speak. Not a big pump, so will take awhile!

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

#### YippeeSkippy

Mod Squad
LifeTime Supporter
Exactly at the 60 line. Stare, with one eye.
Not the stank eye I hope??!

#### thebisch

##### Active member
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
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
I am the OP. Yep, my bad, your right. Either way, I need to drain some water, so a draining I go. Going to start with 1/2 unless advised other wise.

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

YippeeSkippy

#### thebisch

##### Active member
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.

mknauss

#### Chasarms

Silver Supporter
3/4 tap water. Measures at 60. 60 x 3 = 180.
If you were at 75% tap water, you would multiply the result by 4.

mknauss

#### thebisch

##### Active member
Ahhh, so my CYA was 240 then.

If you were at 75% tap water, you would multiply the result by 4.

YippeeSkippy

#### thebisch

##### Active member
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.

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#### YippeeSkippy

Mod Squad
LifeTime Supporter
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

#### mknauss

Mod Squad
TFP Expert
Bronze Supporter
What now? Probably should drain some more and refill, but I "need" to use the pool this weekend.
Keep FC above 10 ppm and use the pool.