How To Seal Aquarium Bulkheads
One of the key aspects of aquarium plumbing is sealing bulkheads properly, especially in reef aquariums where even a small leak can cause major problems.
Whether you are setting up your first saltwater aquarium or dealing with a leaking tank, understanding how to seal an aquarium bulkhead properly will save you from water damage, equipment failure, and the possibility of losing your marine life.
At Reefco Aquariums, we believe that leak detectors are essential aquarium equipment that every hobbyist should have. The HYDROS Leak Detection Kit is extremely affordable and will prevent any major disasters.
What Are Aquarium Bulkheads?
Bulkheads are the gateway between your reef aquarium and the external plumbing system, like an aquarium sump. They allow water to be transferred from one side of the aquarium to the other while maintaining a watertight seal.
A bulkhead is a vital component in drain and return lines in display reef tanks, however, they can also serve different purposes in more complex aquarium setups.
The key to a bulkhead lies in the seal and understanding how the fittings rely on proper placement and patience rather than excessive force. Unlike traditional plumbing applications, aquarium bulkheads need to maintain their seal while faced with constant water pressure and potential tank displacement.
What Is The Best Bulkhead Material?
The material of your aquarium bulkhead will significantly impact the sealing performance. The most common choice for saltwater aquariums is ABS bulkheads as they are reliable and cost-effective. These standard aquarium bulkheads work well for most aquarium applications, and when installed, they provide good sealing.
For larger aquarium systems, you may want to invest in a premium option like Schedule 80 bulkheads. These bulkheads are heavy-duty and include O-rings to maximize sealing. However, they do require larger diameter holes than ABS bulkheads.
Pre-Installing Bulkheads
Before you attempt to seal any bulkhead, you need to prepare properly. First, start by measuring your aquarium tank’s hole diameter accurately using a ruler or caliper. This measurement will determine the size of the bulkhead. Remember, the hole diameter does not correspond directly to the plumbing size, so check a bulkhead sizing chart to ensure it fits properly.
Once you have selected the aquarium bulkhead, clean both the hole and bulkhead thoroughly, as any debris, old silicone, or any foreign objects can affect the seal and cause leaks.
If you need to remove old sealant, carefully use a razor blade and rub the area with alcohol or acetone to ensure the surface is completely clean. You want to pay special attention to the area where the gasket will be in contact with the tank.
Step-By-Step Bulkhead Sealing Process
Installing An Aquarium Bulkhead
-
Disassemble the bulkhead - unscrew the retaining/lock nut that comes pre-installed.
-
Check the gasket/O-ring for any signs of damage, cracks, or deformation - replace it if needed because damaged gaskets/O-rings are the most common cause for leaks.
-
Position the bulkhead with the flange inside the reef tank - the threaded part extending through the hole to the outside/external area of the tank. Ensure that the gasket is sealed against the flange, not the retaining/lock nut. It is extremely important to check that the gasket is on the wet side of the tank.
-
Carefully slide the bulkhead into the hole - there should be minimal resistance. If you do experience resistance, stop. When there is resistance, it’s likely that the bulkhead is too large for the hole, and could crack the glass on the tank if you try to force it.
Sealing The Bulkhead
-
Using your hand, thread the retaining/lock nut onto the bulkhead.
-
Continue tightening the nut with your hand until the gasket starts compressing and the bulkhead feels snug - the bulkhead should not move in the hole.
-
Using pliers or a wrench, add a quarter-turn. Do not overturn the retaining/lock nut, as this can crack the tank and damage the acrylic.
Testing The Aquarium Bulkhead
-
After installing the bulkhead, slowly fill your tank while monitoring the bulkhead for any leaks. Do not worry is there is small seepage after installing, as this is normal. However, if it continues to drip, this indicates that there is a sealing problem that needs fixing.
-
If you detect a leak, tighten the retaining/lock nut with one more quarter-turn. Monitor for a few hours - often, the gasket needs time to compress.
Advanced Aquarium Bulkhead Sealing
If you continuously experience leaking issues, you can use an aquarium-safe silicone sealant on both sides of the gasket. It is essential to use reef-safe silicone products to prevent any harmful chemicals from leaching into the water, harming marine life.
How To Add Silicone To A Bulkhead Seal?
-
Apply a thin layer of silicone on the gasket surfaces. The silicone acts as an additional barrier.
-
Continue to install the gasket as per above.
-
If you are experiencing problematic holes, you can create a permanent seal by applying sealant around the bulkhead area and adding a piece of glass over it from the inside of the tank. This creates a double-sealed system, however, it makes it almost impossible to remove future bulkheads.
Bulkhead Maintenance
Over time, gaskets will deteriorate over time, particularly when exposed to UV sterilization equipment. If you need to remove the bulkhead for maintenance, always remember to replace the gasket. Almost always, reused gaskets will not seal properly, and the cost of a new gasket is much cheaper than the damage costs from a potential leak.
Summary
Properly sealing aquarium bulkheads is a skill that every aquarium hobbyist should master. Selecting quality materials, understanding compression sealing, and following proper installation methods will help you achieve leak-free installations.
If you need help installing your aquarium bulkhead, the Reefco Aquariums team is here to help. Contact us today for a leak-free operation.
