Cloudy Film On My 50

I purchased a used 50 gal. There is a cloudy film on about 1/2 of the glass. I tried to scrape it off with a razor but no go. What causes this and how do I get rid of it? I tried vinegar, but just by adding it to a rag and wiping the inside. Once the tank dries it is still there. Would filling the tank and adding about a gallon of vinegar help if I let it stay in there for 24 hours? I have heard from reefers who say that they can't get rid of it but when the tank is filled up it is invisible. It is definitely a glass tank but the film seems to be almost inside the glass. Help!
Thanks, Steve

 

I am not positive of this but I think that your going to find that it is permanent. I have a old. really old 33 gallon that has that same kind of film or haze on it. i tried everything to remove it but nothing took it off. I have a feeling it comes from constant cleaning with one of those scrubby sponges.

 

Does it disappear when the tank is filled?

 

Kinda, its still as little bit hazy, but since I am using it as a frag tank it no big deal. As a display tank I think I might look into getting another. You could try it though, fill it with tap water and if its not cloudy go with it.

 

Mine cleared right up with adding water. I have a FW tank that has a cloudy film but can't tell with the set up!

 

I agree that it might not be as visible when the tank is full but if you are really not sure you like it I would look for another tank and use that for something else because once you set it up and don't like it that is gonna be a pain in the ass to swap tanks.

 

Well I let the tank soak over the weekend with a gal. of vinegar added to the filled tank. Scraped it with a razorblade and although the film almost disappears with the tank filled, once emptied, the film comes back. I don't know if hanging a T5 fixture on the tank will make the film visible again. I think I will try CLR and if that doesn't work I'll probably just learn to live with it.
Thanks for the advice,
Steve

 

You could try some household baking soda it is a natural abbrasive cleaner I used it on lids for freshwater setup. Just make like a paste with it with a little water in a bowl slap it on take a sponge and scrub and then rinse super good.