Does Glass Really Weigh Twice As Much As Acrylic?

[Egon]

I moved my 450 acrylic with one other guy. We wheeled it into the house on two of those 4 wheeled carpet covered movers you get at home depot. We got on each side and lifted one end on the stand while the other end was still on the wheels. Then we went to the side on the wheels and lifted that end and slid the tank onto the stand. No way we could of done this with glass!