How to get white film off glass cover?

[Dave & Monica]

Sorry for all the posts – I had two fish in the last 2 weeks decide to carpet ride. The glass covers to my tank have a white film and I can’t seem to get it off – I thought it was a calcium deposit so we used CLR (full strength over night), then Coke (mother-in-law remedy), then baking soda, then Vinegar. Nothing takes this white spotty film off the glass – Ideas? I don’t want to use egg crate as it cuts off light and also observed fish jump right through it. (wrasses and fox face)