I'm a brand new pool owner - I've read TFP pool school and this is my first post here.
We just closed on our new house with a pool. The previous owner has taken great care of the pool and equipment, and generally followed TFP methods. Three weeks ago, he did a treatment with ascorbic acid to remove metal staining. He added way too much, 6 lbs instead of the recommended 1 or 2 lbs (this is a 20,000 gallon pool with SWG). Two weeks after the treatment, he tested the chlorine level and found 0 FC. He shocked with liquid bleach and raised FC to 20. At the time the ownership of the house changed hands to me. Today, my first visit to the pool, I checked FC and it was back to 0. To buy myself a little time to figure this out, I added some liquid bleach to raise FC and I also turned the SWG up to 50% (it was on 10%).
Can anyone help me understand what is going on here, and what I need to do next? Is it harmful to have that much ascorbic acid in the pool, or does it eventually go away?
(pH is 7.2; CYA 50; do not have TA measurement; water has some settled pollen but otherwise looks pretty clear)