Nope, you cannot drill a tempered tank and you would know it if you did. The glass would basically shatter. Do a youtube search for drilling tempered glass and check it out, its kinda cool to see....when its not your tank that is.
I may be getting a 125 vs the 150 just cause I hate the depth of the 150 does anyone know if either of these tanks are tempered? Brand will be AGA.
Thanks
Eric