drilling limits

[reefnut]

im very paranoid about putting any holes in any of my tanks.but i think its time to set up a sump and get some equipment out of my tank.just wondering if you have any ideas on reinforcing the glas around the hole and wich pane would be the safest to put the holes in?also am wondering how many holes you guys have in your tanks and the diameter of these holes.

[danny zubot]

I have a 2 inch hole in my tank for a 1.5 inch overflow. Located in the top left corner as seen below. I wanted it higher but the driller said it would comprimize the structural integrity of the glass. I would talk to a tank builder for the best advice for your tank.

[mr_alberta]

I have 7 holes drilled in my tank. 3 holes are 1.75", 2 holes are 3" and 1 hole is 2.5". The glass is 1/2"

You don't have to drill holes if you don't want. You could always use u-tubes and have siphons on your pumps.

[mark]

In the bottom of mine there's 3x3" and 5x1.75" holes. Panel's 69x20" 1/2" thick.

Can't find the reference, but diameter of hole, between edge and hole okay (the edge of my 3" diameter holes are 3" from the outside edge of the panel, tank was built by Bow Valley Aquariums).