Best way to remove bio film on glass

[Potluck]

In the inside of the tank I have a light clear film, I researched it and it's called bio film, do I want to clean that or leave it? If clean it I've tried my scraper, a magna float, and a course cleaning pad for fish tanks, I only did a little spot on the side incase I'm supposed to leave it but it will NOT come off lol

 

[lasersup]

I also face this problem with my fish tank so please do help