CYA 90, FC 6.5, PH 8+

[orlandoan]

Hi Pool Experts! I’ve learned so much reading other threads and the pool school articles and finally (after 5 years of pool ownership) feel like I have a better understanding of pool chemistry.

14k gal pool, plaster, resurfaced April ’23

Test Results
16 days ago I did the OCLT and we had less than 1ppm of loss (12.4 at night - 11.6 in the morning = .8)

6/3
FC 4ppm
CC .2
CYA 100 (after getting this reading we decided to drain the pool ~600 gallons, we needed to top off from evap anyways so we figured we’d drain it some more and added ~900 gallons)
Added 64oz of 10% Liquid Chlorine

6/4
FC 6.5ppm
CC 0
CYA 90
Added 64oz of 10% Liquid Chlorine

6/5
FC 6.5ppm
CC 0
PH 8
Added 1 gal of 10% Liquid Chlorine

Have not tested today 6/6. I will after work.

What should I focus on? Lower PH and maintain FC at the recommended levels ~10? Water is clear, looks nice…we’ve swam in it with FC 9-11 / cya 90.

Edited to add:
March of this year, CH was 420ppm

TA
2/3 120ppm
3/3 100ppm
3/17 100ppm
3/23 100ppm
5/18 120ppm

 

[Texas Splash]

Welcome to TFP! Your CYA is still a bit high, but as long as you keep the FC elevated in the ideal range per the FC/CYA Levels you should be okay. The CYA should slowly start to fall a little each month due to degradation. Yes, watch the pH closely to keep it from going over 7.8 (scale). You didn't show your TA or CH, so that would be good to know as well.

 

[Texas Splash]

Good job on testing your own water. Remember to take advantage of the PoolMath APP and its features. Also look in the profile settings of that app and hit the toggle to share your Poolmath test logs to your TFP profile.

 

[orlandoan]

Good job on testing your own water. Remember to take advantage of the PoolMath APP and its features. Also look in the profile settings of that app and hit the toggle to share your Poolmath test logs to your TFP profile.

thanks for the tip on connecting the app logs to my profile…looks like that works now. Still trying to figure things out with the app...

 

[orlandoan]

Welcome to TFP! Your CYA is still a bit high, but as long as you keep the FC elevated in the ideal range per the FC/CYA Levels you should be okay. The CYA should slowly start to fall a little each month due to degradation. Yes, watch the pH closely to keep it from going over 7.8 (scale). You didn't show your TA or CH, so that would be good to know as well.

Should I add muriatic acid to lower PH first? Wait 30m, test to confirm it’s under 7.8? Then add LC to raise to the ideal range?

Added the below to my original post:
March of this year, CH was 420ppm

TA
2/3 120ppm
3/3 100ppm
3/17 100ppm
3/23 100ppm
5/18 120ppm

 

[Texas Splash]

Should I add muriatic acid to lower PH first?

Sure, but no need to wait 30 min to add chlorine. Once you pour the MA into the water with good circulation, it dissipates quickly. After just a few minutes (say 5) that's plenty of time to add the liquid chlorine.

Now to re-test the pH, yes, give that some time. I'd say about an hour or so.

 

[orlandoan]

Sure, but no need to wait 30 min to add chlorine. Once you pour the MA into the water with good circulation, it dissipates quickly. After just a few minutes (say 5) that's plenty of time to add the liquid chlorine.

Now to re-test the pH, yes, give that some time. I'd say about an hour or so.

thank you for the advice!

 

[orlandoan]

Well we finally got this wet stuff pouring out of the sky last night. It’s been 50 years since I’ve seen …I think it’s called... rain? We nearly have an infinity pool now. Will have to drain it later today so our skimmer can do it’s job, which means double yay…our CYA will get a slight dip.