FahrtAutoRC

We have a Sudan Plated Lizard. Little guy's growing like crazy so to set him up nicer we got a fish tank from my buddy. Basically we're moving him from his 30 gallon to this 60 gallon.

The problem is, he just emptied this tank for us to pick up yesterday, and it's NASTY. The whole inside's covered with a white-ish film that's very stubborn. I tried a soft kitchen scratch pad with vinegar and salt. Nothing. It looked great, until it dried, then it went nasty again. I was able to use a straight razor and get it about 90% clean but it's still hazy and dirty.

Is there any other way to clean it, and/or any suggestions to polish it nice and clean? I'm sure there's some kind of compound out there for polishing glass that would work, but is there an easier or simpler home solution that would do it? I want to get the inside and outside as clean as possible, and the glass as clear as possible because I feel limiting any of his view of the outside world would be horrible, I know I wouldn't want to live like that!!!