I have a 24,000g, vinyl, IG, sand filter, pool in Central NJ. I use just a floating puck for chlorine. I opened the pool in early April and have been struggling with the chlorine ever since. All other levels have remained at what you'll see below with no chemicals. In the beginning I was dumping 3-4 bags of shock, taking an instant strip reading and showing zero chlorine (pool store confirmed). I have used both the filter perfect and line cleaner perfect from Natural Chemistry (can't remember the name) products. I have also used PhosFree and Aqua Finesse. As of last week if I put 2 bags of shock in the pool I was able to get a dark purple reading on the sticks, however by the next morning the reading was back to either nothing or a very light shade of purple. I most recently shocked the pool on Wednesday night. Today I took a water sample to the pool store albite after it rained both Friday all day and today all day:
I also asked them to perform a Nitrate test which was only a stick test but came back in the 1-2 range (between the first and 2nd pink reading on the stick). Nitrites came back zero. I know if nitrates is the problem draining is my only solution, but I can't find what is an "acceptable" range for nitrates.
Does this sound like a Nitrate problem or something else? Any help would be appreciated.