High CYA AND SLAM Target 45

[Brookwood]

Helping an elderly neighbor couple with their pool. Their pool guy was just fired because he couldn't get the pool clear after about 3 months of problems. He had been using chlorine pucks for years so the CYA is very high. He also added a bunch of stuff, copper algaecide, as a final attempt to clear it up. The pool was a deep green color, and was getting that way for a number of weeks. At the end of today's SLAM it is still green but a little lighter.

Vinyl liner
In-ground
24,000 gal
Chlorine via pucks

The day before the SLAM the water tested:
FC 0
Ph 7.2
TA 70
CH 100
CYA 100 or more

I replaced 25% of the water to try to lower CYA, but it still tested 90. I added acid to lower Ph to 7 to help avoid staining from copper algaecide. I decided to use 35 as the target shock, but at 10:30 am I upped it to 45 after a number of cycles because the CYA could be 100 or higher.

Today I started the SLAM and here are today's details.

6/16

7:30 am
FC 14, PoolMath states add 1048 oz liquid chlorine to reach target of 35

8:00 am
FC 20, add 748 oz

8:30
FC 25, add 499 oz

9:00
FC 28, add 349 oz

9:30
FC 30, add 249 oz

10:00
FC 28, add 349 oz

10:30
FC 47, decided to change target shock to 45, no chlorine added

11:30
FC 42, add 150 oz

12:30 pm
FC 45, none added

2:00 pm
FC 44, add 50 oz

3:45 pm
FC 41, add 200 oz

6:15 pm
FC 45, none added

8:30
FC 45, none added.

I'll check levels first thing in the morning. I'm concerned about the CYA being so high and the target shock at 45. I can maintain that level if I need to. Let me know what you think. Thanks for following along. Remember to NOT look at my pool specs when suggesting. This is for my neighbor and their specs are listed above.
Thanks
Sean

 

[jblizzle]

I think you should have changed more water before you SLAMed

Shock level for 90ppm of CYA is 35ppm. There is no reason to go that much higher.

Beyond that you are doing ok.

 

[Brookwood]

Thanks. I had hoped to replace more. The pump quit sending water to waste. I was in my driveway and heard it sucking air through the skimmer valve even though I had closed it. My guess is that in the future we will need to replace water again to work on lowering CYA long term. But, they will stick with the pucks so it is almost in vain.

 

[Brookwood]

6:00 am day 2 and the water definitely looks better. It was hard to see change yesterday but it is lighter now.

FC 40, added 249 oz
CC .5

 

[kimkats]

They can use pucks BUT they have to know they will need to do a water exchange every year or so to keep the CYA in check.

Here at TFP we teach what each thing does to a pool so you can make an informed choose when caring for your pool.

So sweet of you to help them out. I would do another BIG water change to get the CYA down big time. It will speed things up as well.

Kim:cat: