How to build an aquarium – DIY fish tank

In the age of YouTube videos on how to do absolutely everything, the temptation might be to have a go at building your own aquarium. Its only five panes of glass after all – right? But it’s not quite that easy…

Take a look at your aquarium up close and feel it with your fingers. It will have neat silicone lines, smooth, polished edges to the glass and the corners are all square. It may have a trim on the top and bottom, a base frame and probably has some kind of bracing bar.

Low iron glass 

The glass will be float glass, maybe even OptiWhite, meaning its low iron and is clearer than normal glass. Tanks are built in two different ways too. Either the front back and sides are all sat on the base, or clad around it, known as a floating base. Floating bases are neater, the build of choice of premium manufacturers, but a lot harder to build. It may have black or clear silicone, and the silicone will be aquarium safe and of the correct strength for holding several hundred kilos of water in place. 

So to build your own aquarium you’ll need float glass with polished edges so that you don’t cut yourself handling it. You’ll need a glass processor for that, and those five panes of glass may be more expensive than buying a pre-built tank off the shelf. You’ll need to calculate the dimensions that the glass will be cut and polished to, as well as allowing for at least 1mm thickness of silicone inbetween. 2mm for large tanks. 

Chi fish tank
Professionally built aquariums have polished glass edges and neat silicone lines

Braced or braceless?

You’ll need bracing bars to strap the top of the tank and prevent the glass from bowing, or you can go braceless – an easier build – but the glass will need to be thicker than normal and thicker glass may double in price. You’ll need a good glass processor who can work within tolerances as if the front pane is 899mm and the back one 901mm, it won’t be square.

And you’ll need several goes at the silicone work as neat silicone is an artform, and comes from building thousands of tanks. Then you’ll need to let the silicone cure for a few days, and water test it, but if it leaks or unzips in your living room, you’ll have no come back either. DIY tank building is not for the feint hearted!

So the best thing to do is just buy a fish tank off the shelf. It will be safe, watertight, it will have a guarantee and for its size, it will actually work out cheaper than buying like-for-like glass, in many cases. The cabinet will be strength-tested to take the weight and you can set it up in a day and feel safe in the knowledge that it’ll last for many years. 

Posted by on

Jeremy Gay is an author, lifelong fishkeeper, and aquatic specialist. He's a former editor of Practical Fishkeeping Magazine, UK editor at Reefbuilders, a former aquatic store manager, and has collected fish in Sri Lanka and the Amazon. He's been on tv and radio, contributed to Koi Carp and Gardeners World magazines, been a product tester, a judge, and a product developer. Jeremy is here to guide and advise you on all things tropical, pond and marine, from set-up to stocking, health, feeding to breeding, as well as solving many common fishkeeping problems along the way.


Add your comment




* Required fields