All sheet glass is float glass. They melt the sand and additives and pour it on a river of molten tin. The glass is then floated down and cooled while stretched to size. This is how they get it flat and a consistent thickness.I also saw somewhere that the glass is floated on tin as the last step before putting the tank together, and they're supposed to put that side out, but sometimes make a mistake and put the tin side on the inside so you get elevated levels on startup. I could have had loses for some other reason, but that was the only standout on the Triton test.