The height of the tank is the most crucial measurment. Your talking about a tank 25", you'll want to go with .75". How ever, you also talking about a very long tank. I asked my acrylic tank manufacturer and they said 1". 1" acrylic is unbeilably expensive how ever. But then again so is replacing all the carpet and sheet rock in your house. Not to question your skills, but I would have this one built.