To drill or not to drill?
 

I recently setup a new 40 gallon tank. I bought it used with a whole pile of equipment but it also came with an extra 20 gallon long that I intended to run as a frag tank. The display tank currently has a "built in" style sump that runs along the back a lot like a red sea max and works quite well. I would like to increase my total tank volume and also have a frag tank running in-line..

My plans are to drill two holes in the bottom of the display tank to create a herbie style overflow. drilling where the return pump currently sits because, there is enough room. I am looking for your opinions on whether or not to drain the entire display or if i could get away with drilling the sump section of the tank while water still sits on the other side. This all makes a pretty big difference on the amount of time it would take me to drain and move livestock versus just drilling and plumbing.

Thanks in advance.

The bottom panes are often made of tempered glass which shatters when drilled, I would check this first. Other than that if you can get a drill and glass cutter inside it should be fine, just keep the bit well lubricated, go slow when cutting and rinse well when done.

You can always drill a hole in the back pane of glass towards the bottom if the bottom of the tank is tempered as mentioned earlier

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It is definitely not tempered as the return is drilled through the bottom. Is there any major advantages having the tank drilled on the bottom versus it being on the side. I am really only concerned about the bottom pane having pressure from the water on one side and none on the side I was drilling.
Thanks.

they drill the holes and any glass work before tempering , doesnt mean its not tempered .

there are ways to tell using polarized glasses;)

cheers

denny

I think I will try to get in touch with the Spencer who I was told built the tank.. Good catch though!