A bulkhead is a plumbing component that allow a panel made of glass or acrylic to have a watertight hole. Bulkheads is used in aquarium plumbing to allow water to flow between different part of the aquarium system. If a person purchases a bulkhead that has an incorrect size for the application, there is the potential for the bulkhead to leak or flood the aquarium.
Therefore, there are various factor that a person should consider before purchasing a bulkhead for an aquarium system. The size of the bulkhead is one of the most critical factors to consider when installing a bulkhead into an aquarium tank. The size of the bulkhead will determine the rate at which the water can flow through that bulkhead.
How to Choose and Install a Bulkhead for Your Aquarium
If the bulkhead is too small for the aquarium, the small bulkhead will create head pressure and place strain on the aquariums water pump. If the bulkhead is too large, it will waste space within the aquarium and may cause the aquarium’s panel to flex, which may also allow for leak in the aquarium. The turnover rate can be used to calculate the appropriate bulkhead size for an aquarium; five to ten times the aquarium’s volume is the recommended turnover rate.
For example, a 100-gallon aquarium will have a turnover rate of 500 to 1,000 gallon per hour. Aquarium tanks with long pipes and numerous fitting will require a flow rate that is 20% of the total calculated flow; this is due to the effect that the pipes have on the flow of water. Water will behave differently in a gravity drain as opposed to a pressurized return line.
Gravity drains, like those located within the overflow box, will have a lower flow rate than pressurized return lines. This is due to the difference in how water is allowed to flow through these two types of systems. Pressurized return lines will use a return pump to push the water through the bulkhead.
For example, using a bulkhead of the mid-size range for a main drain in the aquarium and a smaller bulkhead for an emergency drain will allow for the aquarium to remain quiet in the case that the main drain becomes clogged. In any aquarium with overflows, it is important to choose the bulkhead for each overflow according to the type of overflow that is installed; otherwise, the bulkhead may be undersized for the aquarium. To drill a hole for the bulkhead, you must measure the aquarium to ensure you can purchase the bulkhead according to the thickness of the aquarium panel.
If the bulkhead is too large for the aquarium panel, it will create stress on the bulkhead and the aquarium panel. For glass, it is recommended to use diamond bit to drill the hole, as well as water cooling for the panel. For acrylic, the speeds at which you drill the acrylic should be slower to ensure it does not melt.
When drilling the aquarium panel, it is important to measure the aquarium panel prior to drilling the hole. Thicker aquarium panels can allow for the installation of bulkheads of larger size. For these reasons, it is impossible to drill into tempered glass.
The material of the bulkhead and the material of the bulkhead’s gasket are two other factor to consider when adding bulkheads to an aquarium. The most common material for bulkheads is PVC; this is due to the fact that PVC resist chemicals. ABS material is used for overflows because it is a very tough plastic.
However, if an aquarium is constructed with both ABS and another type of cement, it is likely that the two material will not adhere to each other. Polypropylene bulkheads are more expensive but used for aquaculture application. Polypropylene bulkheads are usually of the threaded type.
It is also important to ensure that the bulkhead has the correct gasket to prevent leaks. EPDM gaskets are an affordable option for the bulkhead to seal against the panel. Silicone gasket will allow the aquarium to withstand high heat from the aquarium’s lights.
Viton is another type of gasket that resist the medications and ozone commonly added to aquariums to treat the inhabitants. The gasket should be placed on the wet side of the bulkhead; additionally, you should tighten the locknut by hand plus a quarter turn. Using tools to tighten the locknut may damage the bulkhead’s threads.
Using silicone sealant around the bulkhead will reduce the lifespan of the bulkhead installation. Over time, the locknut should not be overtightened; overtightening will crack the aquarium’s panel. Depending upon the type of overflow that is used within an aquarium, bulkheads will be used in different ways.
For instance, a Durso overflow will use a single pipe with an air bleed to allow for the water to drain in a quiet manner from the aquarium tank. A Herbie overflow will use two pipes, one for the siphon to the overflow tank and the other to allow for an emergency drain. A Bean Animal overflow uses three pipes that allow the aquarium to be quiet during high flow rate of water.
A return line will often be placed low within the sump to which the aquarium water is returned. Additionally, return lines often use unions for the pump to make swapping them easier. Because gravity drains must work against the friction of the return line, bulkheads for gravity drains must be larger in size than other type of bulkheads.
Aquarium plumbing layouts should be drawn out on paper prior to installing the bulkheads. Additionally, using a bulkhead that is one size larger than necessary will allow the aquarium’s pump to last longer. To properly install the bulkhead, the location of the bulkhead on the aquarium panel should be measured at least two inch from the edge of the panel.
Additionally, the spot where the bulkhead will be drilled should be taped. Use the bulkhead’s coolant to slowly drill into the aquarium panel. Place the gasket into the hole and insert the bulkhead into the panel.
Place the locknut for the bulkhead on the outside of the aquarium panel and tighten the locknut to the panel. After installing the bulkhead, fill the aquarium slowly to ensure there are no leak. If there is a drip, it may be possible to install the locknut tighter.
The most common reason for bulkhead failure are drilling into wet aquarium tanks, not considering the thickness of the aquarium panel, and overtightening the locknut. Overtightening the locknut will damage the aquarium panel over time. You should of checked the panel first.
