Bulkhead Fittings 101

While we’re usually dealing with folks who really know their stuff when it comes to bulkhead fittings and fish tanks, we do get folks who are new to it all, or just getting their bearings as they venture into the realm of being an advanced aquarist.

For those of you who fit the description above, then today’s blog is for you! Today, we’re going to be discussing the absolute basics about bulkheads and bulkhead fittings. You’ll learn about what they are, what they’re made up of and what you should be looking for when you buy one. Let’s jump right in!

What they are

Bulkhead fittings are designed to allow for the drainage of one water (or liquid source) through a specific hole in said source. In our case, this would be an aquarium. The bulkheads create a seal that helps prevent water from leaking out and allows you to quickly remove the water whenever it needs to be cleaned or replaced. There are a wide range of different types of bulkheads that you can use in a tank depending on what your specific need might be.

The basic components

Bulkheads are made up of three main parts. There’s the body, the gasket and the nut. The body possesses both the interior and exterior threads. The gasket which fills the spaces between two surfaces. The last part – the nut – sits up against the gasket and presses into it to create the seal.

What to look for

There are several factors to consider when you’re purchasing a bulkhead fitting. First and foremost, you’ll want to make sure you’re purchasing the right sized thread and the size of the fitting itself. These things tend to be precise, so you’ll want to discuss this with a professional. Most dealers will be able to help you without an issue.

The last thing is understanding the piping and the material you’re going to be using for the fitting itself. Bulkheads come in a variety of makes – all with differences in both quality and strength – so you’ll want to buy material that will be able to balance your needs with longevity and durability.


For any significant and expanded aquarium – bulkhead fittings are a must. Hopefully this guide will give you a starting point. Speaking of that, we’re sure this will leave you with questions as well, so feel free to reach out to us at any time and we can help you get started. Good luck!

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