Chlorine problems

I have a fiberglass pool, 9000 gallons. Water balancing has always been tricky. Chlorine will read 1 or zero most of the time, unless I’ve just shocked the pool. Last week I went through 9 three inch tabs of chlorine  in my Heyward Inline Cholorinator, and after shocking I still have a low chlorine reading of only a .5. (I have even added a gallon of stabilizer as directed by Leslie’s new water analysis system, but to no avail).

I have had a high alaklinity reading of 18 ppm, so dry acid has been added. This morning the reading for alkalinity is now at 4.6 and the ph is at 6.5. I have just added 2 pounds of soda ash.

All of this to information to ask, “Could the high alkalinity level be neuteralizing the chlorine?”

Anyone have any insight?

Hello,

I’ve a Hayward CL200. I had Chlorine 5, Alkalinity 90 and PH 7.5 yesterday in the evening. I use Chlorine neutralizers: Sodium Sulfite and Sodium Thiosulfate. As a rule, 60 grams reduces the chlorine level in my pool by 1ppm.

https://poolforthought.com/lowering-swimming-pool-chlorine

Chemistry case study: Sodium Sulfite | Sodium Thiosulfate