CYA test results (new pool owner)

[JimBurrrr]

Hi everyone, I just purchased a house with a 15' above ground pool. doing the math puts me at around 5,300 gallon. I've been doing the pool store testing every week, and just recently purchased the taylor k-2006 test kit.
anyway the only thing im not to sure of is the CYA level. when i do the test i don't get anywhere near the 100 PPM mark before the black dot disappears, putting me well over 100ppm CYA.
here are my readings from the test kit.
FC -9.5
CC- 0.5
PH - 7.0
TA - 40
CH - 40
CYA???
i tested twice because it was the first time using the test kit and the numbers were pretty much the same.

these are the results from the pool store test performed a couple hours apart.
FC - 4
?Total available chlorine 4?
CH 120
CYA 70
PH 7.2
TA 40

im not sure what to do about the CYA level in the pool. the previous home owner was using the 3'' triclor pucks and i had been using them as well because they left entire bucket full. but after reading through the forum and pool school i want to go the the trouble free route.

 

[Texas Splash]

Hello and welcome to TFP! To confirm a CYA that is elevated over 100, please do the diluted test as noted on the TFP Pool School - CYA page, Step 8. Post back and we'll help you from there. Great to have you with us.

 

[JimBurrrr]

Thanks for the quick help and quick reply. I just did the diluted test, and I'm still well under the 100 mark. I'm guessing my CYA level is well over 200ppm. is it possible the pool store test is that far off?

 

[Philo]

YES!

 

[Akathisia]

Drain and refill to lower CYA.

 

[JimBurrrr]

Drain and refill to lower CYA.

so to drain the pool since the skimmer is up high (above ground pool) and thats my only return to the filter can i hook the vacuum hose to the skimmer and backwash to waste to drain the pool? or will this be bad for the pump?
and doing the pool math it shows i need to drain about 80% of the pool water, so my plan would be to break it up into 3 - 4 drain and refills. after each refill with fresh water should i check the pool chemical levels and add chlorine as needed? or wait until i have the CYA level in check?
EDIT
also my pool water is crystal clear. is this CYA problem something i can ignore untill the summer is over and just take care of in september when i close the pool for the season? or will this do more harm then good?

 

[Mike1162]

It'll waste it lot of water to do several drain/refills instead of one. You can siphon the water quickly with your vacuum hose. Any idea how old the liner is?

 

[JimBurrrr]

not sure how old the liner is. i just purchased the house in may and the sellers didnt specify the age of the pool. my best guess is less then 5 years old, everything looks good and not really worn out.

 

[Mike1162]

You should be safe draining down to 12 inches. You can also do the CYA test with 3 parts tap water to one part pool water. Multiply results by 4.

 

[Pool Amateur]

Glad your pool is still clear but it may not be sanitized, and therefore not truly safe to swim. The Chlorine/CYA Chart extended by Chem Geek is here. Clck on it to take you to the link. As you can see at 120 ppm of CYA (highest the chart goes) you should have a min FC of 8.7 ppm and your target so you do not go below the min of 8.7 is 13.6. Above FC=10 ph is no longer reliable test.

I would believe your Taylor test kit, when I first started I took a sample to 3 different pool stores and got 3 different readings not even close. They can be very far off.

 

[JimBurrrr]

Ok, I'm in the process of draining the pool now, and in a few hours i should be able to start filling it. after I've filled the pool with fresh water what should my next steps be?
should i SLAM it, or do i need to do something before that?

 

[Pool Amateur]

For above ground liner pool do not drain lower than 1', so liner does not shift and cause wrinkles. When pool filled, test water again, adjust ph to 7.2. Check CYA should be above 30 to start SLAM. Then start SLAM. Here is link to SLAM directions, worth a read through to be sure you/I are not missing something.