What Is A Bulkhead Fitting For Aquaponics

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Last Updated on October 31, 2022

The question we’re going to be answering today is: what is a bulkhead fitting? A bulkhead fitting is a point of attachment for connecting pipes to tanks or reservoirs.

Bulkhead fitting helps secure your piping connections thereby preventing leakage. It also helps give the right direction to where water is required to flow through.

Bulkhead fittings are especially used in hydroponics or aquaponics plumbing connections. These fittings are used to fill water or drain water easily from your hydroponics or aquaponics system.

Let’s discuss further the key components of bulkhead fittings, how to install a bulkhead fitting, and their uses.

Main Parts Of Bulkhead Fitting

Bulkhead fitting materials are usually made of fortified and long-lasting components such as PVC, brass, plastic, and other quality materials. Most parts you will find in bulkhead fittings consist mainly of 3 parts.

  • Body of Bulkhead: the first part of the bulkhead is the body which is the exterior and interior threads.
  • Gasket: the next part of the bulkhead is the gasket. It might come in one or two. The gasket will fit onto the body of the bulkhead.
  • Nut: the third and last part is the nut or locknut. The nut is attached to the exterior thread. It will thread into the place of the bulkhead fittings seating up against the gasket thereby creating a tightly sealed water tank.

Outus PVC Bulkhead Fitting for Rain Barrels, Aquariums, Ponds, or Water Tanks

Let’s move forward by learning how to install the bulkhead fittings.

How To Install A Bulkhead Fitting

Below are the steps to installing bulkhead fittings:

1. Hole Drilling: a bulkhead fitting is installed by first cutting or drilling a hole by the bottom of the tank or reservoir to which the pipes can be connected. Make sure you measure and determine the size of the bulkhead exterior so you know the size of the hole to drill.

2. Bulkhead Fitting: after drilling the hole, you can now insert the bulkhead fitting with the threads inside or outside the tank or reservoir (whichever way you want it to fit your connections).

3. Gasket and Locknut Fittings: then fit the gasket into place. If you have two gaskets, use each one on either side of the walls. Now thread the locknut down by tightening it with your hand to apply pressure to the gasket. The locknut will then provide a good tight liquid seal with no leaks. But make sure not to over-tighten too much so you don’t break or distort the gasket thereby causing a leak.

Having fixed all that, you can now go-ahead to connect any type of pipes or PVC fittings.

Benefits Of Using Bulkhead Fittings

  • Bulkhead fitting will create a perfectly tight liquid sealed connection.
  • They are great for hydroponics or aquaponics plumbing connections.
  • They allow for easy flow of water through the tanks or reservoir.
  • There’s no problem with water leakage with bulkhead fittings.

Other Uses of Bulkhead Pipe Fitting

  • They are used in hot water pipe systems especially the brass bulkhead fittings.
  • Bulkhead fittings are used in hydroponic and aquaponic systems for connecting pipes to allow easy drainage along with the water tank or reservoir.
  • They are also used in ponds for installing water to connect pipes that enable easy drainage. This makes changing water easier rather than scooping water out of the bucket.
  • The kitchen sink also makes use of several bulkhead fittings for easy flow of water.
  • Generally used in transporting liquid containers.
  • They are as well used in any type of mechanism that requires large drums or barrels that needs to be filled with water.
Other Uses of Bulkhead Fittings

What To Consider When Purchasing Bulkhead Fittings

Anytime you purchase a bulkhead fitting, always consider the type of liquid that will flow through your fittings. If it is a hot liquid you should go for the strong type such as the brass bulkhead fittings. If you will be working with cool water you can go for the regular type.

Also, put into consideration the speed or pressure at which your water will be flowing. For instance, high speed or pressure will need a strong fitting and vice versa.

All these considerations are to make sure you don’t end up with a distorted or cracked gasket due to pressure. The goal is to prevent any leakage.

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What is a bulkhead fitting?

The most common bulkhead fitting for aquaponics is the standard 1-1/4" x 1-1/2" copper pipe. This is an ideal fit for a single tank setup, where you have one sump and one fish tank. However, the 1-1/4" diameter of the pipe is also too large to be easily used in multiple tanks (more on that later). 

It is a good choice for any aquaponic system where there is only one fish tank or sump, but it is not suitable for multiple tanks. It is also not recommended for systems where water must pass through a filter. Most standard 1-1/4" x 1-1/2" copper pipes are made with 1/8" thick walls, which is not strong enough for more than one tank. If you have more than one tank in your system, you will need to upgrade to a stronger bulkhead fitting. If you are planning to put your aquaponics in multiple tanks, you should use a bulkhead fitting that has at least 3/8" thick walls.

How do you install a bulkhead fitting?

The standard method is to use a drill and a 1/4" bit. If you don't have a drill, then you can use a 1/4" drill bit. Attach the bulkhead fitting to the edge of the wall with a screw. Drill a hole through the bulkhead fitting and into the stud. Insert a washer (or two) into the hole.

Attach the screw into the bulkhead fitting, and the washer will hold it in place.

How do I stop bulkhead fitting from leaking?

There are many reasons why you might have a leak. First, I would check your system for leaks in the main tank or other components. If you find any, they will need to be repaired before anything else. Second, I would take a good look at the fitting and see if you can identify what is causing the leak. Some leaks occur because of manufacturing defects. Others occur because of damage to the fitting. You may have to disassemble the bulkhead to get a better view.

Third, you may need to look at the valve that controls the flow of water. If the valve is damaged, it could be leaking as well.

How do you replace a bulkhead?

The best thing to do would be to remove the old one and then install the new one. If it is a solid piece of material, it may be difficult to remove without destroying it, but if you can cut it off with a hacksaw or similar tool, it shouldn't take more than an hour or two to do so. 

Once the old one is removed, install the new one

How do you seal a bulkhead fitting?

If your bulkhead is a simple pipe fitting that has no special features (eg, a threaded nut), then there is no need for a seal. The pipe will be pressed tightly against the wall of the tank, so there won't be any leakage. If your pipe fitting has a threaded nut, then you'll need to use an appropriate sealant to prevent leakage.


With that said, we do hope you have grabbed one or two things about what a bulkhead fitting is. If you have any questions feel free to drop a comment and we will respond.

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