My friend is offering me a 40 gallon tank. Problem is is that he used it for a lizard and we can't tell if it's an aquarium or not. It fits all the dimensions of one that size 36x18x16 with 6mm glass thickness. He doesn't remember what it's called or the brand that made it. He only remembers buying it from Petco like 5 years ago. I need to figure out if I can use it or not.