High Chlorine Levels & CYA?

[flynnst0ne]

We had our pool resurfaced/new sand filter about 2 years ago.

i haven’t kept up with any chemicals over the winter, and just started getting it ready for spring. The surface had a couple minor algae spots, so after a brush down/backwash i shocked the pool with 2 gallons of Hasa Sani-Clor. Jug says 12.5% Sodium Hypochlorite and 87.5% other ingredients. I completed another backwash

I tested the water with a TF100 kit, and After 3 days, the chlorine level isn’t dropping.

Water Results are as follows:
FC = 43
CH = 525
TA = 100
CYA = 120-ish+
ran out of red phenol to test the PH.

The water doesn’t look bad, but does have a very slight haze.

not sure why the CYA is so high after 2 years? Do i need to drain and refill?

 

[Oly]

Your pH test is not accurate above 10ppm FC.
Did you test your CYA using a diluted sample to determine the 120ppm?
If your CYA is that high (maybe higher) replacing some of the water with fresh will be required.

Also 2 gallons of 12.5% liquid chlorine in your 13,000 gallon pool will raise the FC 19ppm.

 

[Oly]

 

[flynnst0ne]

I

Your pH test is not accurate above 10ppm FC.
Did you test your CYA using a diluted sample to determine the 120ppm?
If your CYA is that high (maybe higher) replacing some of the water with fresh will be required.

Also 2 gallons of 12.5% liquid chlorine in your 13,000 gallon pool will raise the FC 19ppm.

i used the CYA test from the TF100 kit. Pulled the water from the pool this morning.

Why would the FC test so high then if i only put in 2 gallons? Can the test kit/chemicals go bad? I’ve had the kit 2 years or so...

 

[mknauss]

How have you been chlorinating your pool water?

Reagents can last two years if kept in a cool, dry place. So indoors in Arizona. If not, you need a complete refill set.

 

[Oly]

The CYA test tops out at 100ppm. If you are at 100ppm then you should dilute your pool water sample by 50% with tap water and run the test again and double the results for a more accurate reading.

Test the FC again. Clean the test tube with tap water and then rinse again with pool water. Fill to the 10 ml mark with pool water and retest. Each drop to clear the pink will now equal 0.5ppm.

 

[flynnst0ne]

How have you been chlorinating your pool water?

Reagents can last two years if kept in a cool, dry place. So indoors in Arizona. If not, you need a complete refill set.

The pool water hasn’t been chlorinated since December (up until now).

the reagents have been stored indoors in a cupboard for 2 years... just seems odd how far off everything is measuring

 

[flynnst0ne]

The CYA test tops out at 100ppm. If you are at 100ppm then you should dilute your pool water sample by 50% with tap water and run the test again and double the results for a more accurate reading.

Test the FC again. Clean the test tube with tap water and then rinse again with pool water. Fill to the 10 ml mark with pool water and retest. Each drop to clear the pink will now equal 0.5ppm.

just redid the FC test. It took 90 drops of R0871 to turn light pink/clear

 

[Oly]

How much water did you test?

If you tested a 25ml sample then your FC is 22.5ppm.
If it was a 10ml sample then FC is 40ppm

 

[flynnst0ne]

How much water did you test?

If you tested a 25ml sample then your FC is 22.5ppm.
If it was a 10ml sample then FC is 40ppm

It was a 10ml sample