New to TFP need advice

[roallen61]

Hello all my first question , Thanks in advance to any replies
My CYA is too high. I have back washed to waste multiple times bottom of skimmers and fill with fresh water from well.
How much water should I dump ?
I just got a Tf 100 kit with below results
CYA-beyond 100 just guessing 400
Chrorine - 0-1
ALK -400 +
PH- 8.2

 

[Isaac-1]

Have you tried the extended CYA test Extended Test Kit Directions This should give us an idea of how high your CYA really is, if it really is at 400 then you will need to replace about 90% of your water, since you have a vinyl pool you will want to do a series of partial drains so as to always keep about 1 ft of water in the shallow end to prevent the liner from lifting and getting wrinkles. I would suggest retesting after each partial drain / refill cycle, repeated as needed until your CYA gets below 50 ppm.

 

[roallen61]

Thanks for advise
I added 1/2 jug 12.5 % bleach pm. Then retested this am using extended CYA test. results from pool math suggest draining 60%. I also need to lower PH.

Can I drop CYA by backwashing to waste say over 4-5 days days ? and should I adjust PH now ? I would like to keep swimming
CYA- 100
PH- 8.2
Alk- 140
Chloro - 4
CC - .5

 

[Texas Splash]

I concur with Isaac-1 in that a significant drain is the best option as soon as you can do it. Until then you are kind of wasting chemicals that will get flushed-out anyways. Yes, backwashing to waste will reduce CYA overtime, but that's a lot of backwashing. So if you need to give everyone some swim time, go ahead and adjust pH for now, but then plan on doing a significant water exchange as soon as possible. Just in case you've never done this, here's the dilution testing method:

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.

 

[roallen61]

Thanks, Texas Splash and Isaac-1
I hoping there was an alternative to drain so much water. I did use dilution method to get an accurate CYA number.
Glad I wised up and started my own testing. As pool store continued to sell me things I did not need even when i pointed out high levels of CYA on their test results. They advised to add Phosphate.

Thanks again for your responses and to TFP