aquarium glass drilling

Hobbyists have been modifying their tanks for years now. Some of us are intimidated by the idea, but like anything else, once you understand it, and what and why we’re doing it, things get clearer, and easier. This post will hopefully help educate everyone and help them move forward as DIYers.


This is the first question we need to ask. Most of the time the answer is yes. However, there is always something in the great scheme of things and manufactures that makes us promote this question.

There are 2 basic types of glass used in the aquarium hobby. Regular plate glass, and tempered glass. While plate glass is easily drilled, tempered glass cannot be drilled.

While there are several ways to detect tempered glass, I would always recommend reaching out to the manufacture for details about the aquarium before drilling. As a rule of thumb, I don’t drill anything smaller than a 40 gallon aquarium, and when doing so I understand the risk involved.

aquarium glass drilling
aquarium glass drilling


Most overflow kits come with a template, but if this isn’t provided, you will either have to buy one or make it. The bit must have a guild to keep it on point. Without a template, the bit will wander and the alinement you need will not fit.


One problem with cutting your own holes is blowout or scalloping of the glass on the opposite side of your cut. Is happens because the glass is thinner and is no longer supported. I use the heaviest clear packaging tape I can find. I also don’t apply a lot of pressure during the last part of the cut. Chipping on some level will occur, but it can be limited by the cutting force, and backing the cut with some type of ridged tape.

aquarium glass drilling
aquarium glass drilling


Make sure you have plenty of water, lightly rock the bit back and forth, let the weight of the drill do the work, take your time, and use proper personal protection. These are things you here all the time when drilling glass, but no one ever really tells you to get comfortable. Drilling glass isn’t like drilling wood or metal. With softer materials you can almost always see your progress, but with glass, it’s a lot slower. So, get comfortable, stay in the moment, pay attention to what it is you are doing, and you’ll be successful.

If you're in the Murfreesboro Area

animal city

Please stop by Animal City on NW Broad St. They have high quality fish  and their staff is more than helpful!

If you're in the Nashville Area

aquatic critter

Visit Aquatic Critter on Nolensville Road. Huge selection of fish and equipment, and their staff is very knowgledable!