My Test results:

FAC - 3
TAC - 3
Salt - 4500 (High) - fixing this
Calcium Hardness - 140 (low) adding the recommend amount slowly and retesting after 4 hours
Cyanuric Acid - 25 (low) - need to get some
Total Alkalinity - 90
pH - 7.4
Copper - 0
Iron - 0

We have a 33,000 gallon pool with a DE filter. We cleaned the DE filter by removing oils first then an acid bath. Its running perfectly fine. All systems are running great. We opened the pool 2 weeks ago. Got all the levels good. Salt was low. Made the mistake of testing then adding salt when it was cold. We are fixing this. My concern is the white film on top of our pool. I have no idea what is causing this and never seen this before. Any suggestion would be appreciated.

Thank you,