New girl

I'm not calling you out or anything.... Just want to know how I can be sure the backsides are NOT tempered. Is this how all glass tanks are? There is a sticker on the bottom of the tank that says it was manufactured in March 1995. If possible, I would much rather have a drilled tank than to have to deal with an overflow box.
that sticker will usually say if any of the glass is tempered, mine says the bottom is tempered and it's a 60g, also, there might be a sticker on the crossmember at the top of the tank telling what is and isnt tempered
Usually backs are the last to be tempered. It could be, but most 125's are bottom only, but you made me think of a good point: unless you can tell front from back, it doesnt matter which side is tempered unless you get lucky. Can you see any edges of the front or back? If you can send me a side picture of the edge, I can probably tell you. I work for a glass company. : )
Kyle, I took two pics of the tank and put them in an album here on Livingreefs entitled "Is my glass tank tempered or not?" I do not know how to link the album to a message/post.
Chips all I needed. : ) Drill away. Tempered wont chip, if an object hit annealled glass (plain sheet glass) hard enough to chip, its drillable. Tempered glass is weakest at the edges and wouldve exploded. Its so sensitive that if we so much as nick concrete, metal, brick, etc...we have to order more. Yet you can beat the pane all day long and only hurt yourself. Ive got some cool stories if youre interested. : )
Then "Drill away" it is. I'll have to do some research on what size bulkheads and PVC to use. There's plenty of U tube vids on drilling glass. I'm also wondering, how many holes to drill ??? 2 or 4. or possibly 3. Drains and returns.
They have some cool videos on youtube. A smartphone and a pair of uv sunglasses. I believe it is titled "how to know if my glass is tempered" i would check that out first before id drill.