Aquarium Glass Hole Cutting


How to Drill a Glass Hole

Already have an aquarium? So long as it is not tempered, and it is thick enough to support the pressure of water after the hole is drilled (minimum 1/2" recommended) you can easily drill a hole yourself to add an H2Overflow® or Siphon Stopper® return fitting to your existing aquarium.

Glass Hole Cutting

Click Here to Order Glass Hole Cutters and Templates


Notice: Any time you drill a hole in glass there is a risk of failure. We will give advice as to best practices for cutting glass holes, but we do not guarantee success. Drill holes in your aquarium, or aquariums purchased form us at your own risk. We do not warranty aquariums that are broken from drilling your own glass hole.

1) Use a Template

Because glass hole cutters do not have a mandrel or a pilot hole, it is important to use an adequate template to keep your drill bit centered. We also recommend a backer so when your glass hole cutter breaks through the other side you minimize chipping of the glass. Some chipping is likely inevitable and can be smoothed out with hand sanding with sandpaper. Be sure to rotate your backer between every hole so you have a flat surface on the other side each time you cut a new hole.

Make Your Own or Purchase a Template

We have an image template you can download and print to make your own wood template (3/4" plywood recommended), or you can purchase a pre-made wood template from us. This template will have the correct spacing from the bottom of the frame of the tank to the center of the hole if you are drilling a hole for our H2Overflow® or our Siphon Stopper® system. It also has a wedge to allow for coolant (water) to be applied and for the glass debris to exit while drilling.

Be Careful of Spacing

A general rule of thumb is to never go closer than 3" from any edge or another hole, and the further you are away from another hole or any edge the better. Also, try not to drill too many holes. There is no definite answer as to how many is too many; every situation is different, just don't drill more than you need. Also keep in mind, our template has the 1-1/8" hole very close to the 2-3/8" hole. This is not intended to drill these holes this close together, it is for template purposes only! You should re-position and re-clamp the template between drilling each individual hole and make sure they are not too close together!

DOWNLOAD Our Image Template Here: Glass-Hole-Template.PDF

2) Use a Proper Glass Hole Cutter and Drill

We have glass hole cutters available for low volume glass hole cutting (5-10 holes). There are more expensive cutters available online on other web sites that can last much longer if you have a lot of holes to cut. Make sure you use a drill with a side handle to prevent the bit from binding up and hurting your wrist, and possibly causing damage to your aquarium.

3) Use Coolant

Some type of coolant is recommended while cutting your glass hole. We typically use running water.

4) Be Careful!

Each drill bit has a recommended RPM. As far as applied pressure, just take it easy and don't force it. Remember, glass edges are sharp, so be careful with the exposed edge of the hole and the remnant when you are done so you do not cut yourself.

Better yet... buy the aquarium from us, and we will cut the hole for you!

Please be sure to look into our other Custom Aquarium supplies today!