[Another] CYA Issue

Jump to latest Follow Reply
Mickey Moose

Mickey Moose

Well-known member
Jul 28, 2015
116
Dallas, TX
On 11/23/2017 my CYA measured 30. Haven't measured since then until two days ago and found it was zero. Poolmath says to add 139 oz by weight (to reach my goal of 40) so I picked up an 8 pound bucket. I've added about 6 pounds over the last two days and I'm getting a reading now. When the TF-100 view tube is *completely* full I can just barely see the black dot... or maybe I can barely "see" it because I know it's there. The top most hash mark is 20 so the measure is something less than 20. Does it seem I'm on the right track?

Thanks.
 
The water is crystal clear and is mid-70s. CCs are 0.5 or 0. I had been losing a lot of chlorine so two consecutive nights I performed overnight loss tests. Each was 0.5. Next, I was able to determine the loss was occurring during the day. I have been maintaining chlorine for a target CYA of 40 but this has been a battle.

FC loss for the two weeks ending prior to the other day when I started adding CYA was 5.2. FC loss for the last two days has been 1. So, I guess I'm confused about how so little CYA can have such a big impact on FC loss... see original post for CYA numbers.
 
Last edited:
If you have direct sun on your pool daily, with a CYA of 40 you will be losing more chlorine to UV exposure.
I've often seen posts indicating that in your region a CYA of 50 or even 60 is recommended.

I tried getting by with CYA of 30 but I have to have mine at 50 otherwise I lose more chlorine too
and I'm in the pacific nw. During the swim season I do cover the pool with a blue bubble blanket
and that helps keep the chlorine levels higher. But I mainly use it to keep the water from losing heat
and water evaporation over night.
 
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply