I have thoroughly read and re-read the thread It Can Happen to Anyone By Richard aka Chem Geek. Sorry, I don't know how to create a link to the thread. I found this post after searching similarities to what is happening to my pool. Without a long background of how I got here (bad choices that lead to an algae bloom which I have cleaned up), I will let you know where I am currently and ask some questions.
As of 4pm MDT 6.21.13
CYA=20? (There is cloudiness to the sample water but my comparator only measures to 30)
The pool water is clear and pool looks good, however at night the pool lights show some cloudiness.
I have added 8#s of cyanuric acid over the last 5 days with no back-washing only to register maybe 20ppm. I have twice superchlorination (shock) treated the pool with 10x the CC value or more to reduce the CC. Shock value #1 was 20ppm when CC=1.8ppm Shock value
#2 was 15ppm when CC=1.2ppm
As you may have guessed none of this has completely solved my issue. Today, after reading the above mentioned post I purchased an ammonia test kit (salicylate test which matches to shades of yellow to green on a color card) from a local tropical fish store. I used the freshwater match card. My pool does not use saltwater other than the residual from the 8.25% bleach used for chlorination.
Result equals between 1pmm to 2pmm of ammonia! The color match is closer but not equal to 2ppm of ammonia.
Prior to my mistakes, my pool was operating well since opening and a month later with the following readings...
FC=3-4ppm with regular chlorine maintenance.
pH of 7.5
CH went up 'cuz I used 73% Cal-Hypo in the 1st shock treatment. Have used only 8.25% bleach in the 2nd shock. I don't know what has caused ph & TA changes. OK, I am not a chemistry whiz, so simple answers are appreciated. Here are my questions.
1. Richard's post states he put in over 68+pmm of chlorine in one day to reduce the CC and remove the ammonia. His pool is 16000 gals, he had 0.8ppm of CC and 2ppm of ammonia when he started the extreme chlorination. Is there a formula to calculate FC ppms I may need based on my pool's #of Gallons, CC, Ammonia values or any other factors I'm not considering?
2. After calculating the amount of needed chlorine should I add, can I do it at one time or need to divide into a #number of additions at certain ppms of chlorine. Richard added chlorine in 5-6 intervals. I'm not sure why or maybe there is not a formula as requested in question #1. I'm hoping I could do it in 1 more shock treatment.
3. Richard added cyanuric acid in between intervals of chlorination. It seems logical to me to add this after the ammonia is 0ppm, but I'm not a chem person. Any guidelines would be helpful.