"tempered glass bottom. Do not drill"

So i am cleaning out the tank today and noticed a sticker

"TEMPERED GLASS BOTTOM. DO NOT DRILL"

So im guessing I can not drill through the bottom. But what about the sides? Can i still drill through there? What are the pro's and con's of a drilled tank? I start by saying I can plumb my way to my future sump easier. Are there templates or locations where the drilling should be done?

I have lots of questions.

 

I just took mine to a glass shop. I'm all for the DIY but I wanted peace of mind when it comes to the glass box that holds everything together.

 

Professional glass workers have tools that can safely drill tempered glass. Usually the walls are not tempered, but it's not always the case. Having a drilled tank will allow you to drain water into a sump without the chance of a siphon break in an hang-on overflow. If you want to drill, you will want to get an overflow chamber made, or buy one. You can just add a bulkhead and attach a strainer as well though. You will want to drill down from the top of the tank at least twice the thickness of the glass, if that makes sense. I would say drill at least 1.5" to 3" or so from the top, depending on how thick your tank wall is.

 

I drill tanks for LFS... it's not as hard as you think but most people would rather have the piece of mind. You can make your own template out of wood if you want but not neccessary. DO NOT DRILL the bottom w/o experience. It can be done but I even blew my own tank out... it's a dice roll. The sides are not tempered... drill away. The bit cost 15 bucks probably around what you would pay depending on the thickness of your tank in upwards to $25. For $10... is it worth your piece of mind?

 

Pros... you never have to worry about over filling the tank during a power out. I had a cpr (and I drill tanks.. lol) and the pump didn't suck when the power came back on... whooooo messy and fishy a couple days later. That is the biggest advancement.
Cons... you have a bulkhead and pipe sticking out of your tank from the back, not like the box wasn't there anyway but it's there.

 

You should be ok to drill the sides. What size tank is it? Marineland's 55 gallons tanks have tempered glass sides as well as the bottom. It's the only size they do that with. If in doubt call the manufacturer.

 

Who told you this ? Its totally untrue Maybe they are confused about tempered and laminated glass ? But tempered glass cannot be drilled, but untempered laminated glass could (probably) be drilled with proper tools . But all of the holes in tempered glass are drilled and or casted into the sheets before tempering

 

I agree. Tempered glass CANNOT be drilled. Also saying that the sides are not tempered is an incorrect statement. I just attemped to drill a 55 gallon on the end about a week ago and blew it out. If you want to find out if the sides are tempered, grab a pair of polarized sunglasses and see if there are designs in the glass. (you will know when you see it) If these are present then it is tempered.

 

Usually anything between 40-65 is tempered to save on glass thickness... I know 40 breeders are glass sides at least, most 55s are fully tempered, but this is what I heard from the LFS in town here.

 

It was a local glass shop here in my town where I bought my glass sheets when I made my first fuge. Maybe they misunderstood what I said, I don't know. I only relayed what they told me. Personally, I would never even consider messing with tempered glass, there is way too much water pressure and weight on the bottom of the tank for that. What I have read was that any modifications to tempered glass was done prior to tempering. Those guys in my local shop said "no it's possible, there are special tools that can cut tempered glass." I don't know if cutting is different than drilling though.