Reef Tank Plumbing Guide – Designs, Diagrams, Sump, Overflow, Return

Reef Tank Plumbing Guide – Designs, Diagrams, Sump, Overflow, Return


Reef tank plumbing is a necessity unless you purchase an all-in-one aquarium. We’ll cover designs, plumbing diagrams, parts, the overflow (Durso, Herbie, & Bean Animal), the return line and return pumps. Even with an all-in-one aquarium you may want to re-plumb it to ensure that it is quiet and reliable.

While it’s possible to do without a sump, it’s not recommended. A sump provides extra water volume for better stability as well as a place to hide equipment. Also, larger and more effective equipment fits in a sump as opposed to hang-on-back (HOB) equipment. Besides, who wants to see a tank with all kinds of equipment hanging off of it?

Main sections of Reef Tank Plumbing

  • Overflows
  • Sumps
  • Returns

Basic Saltwater Tank w/Sump – Plumbing Diagram

saltwater aquarium plumbing diagram


Simply put, an overflow is an inlet for your reef tank plumbing. Water enters the overflow and down to the sump.

2 Main Types of Overflows

Internal Overflows

By far, the preferred type because it’s much safer. However, it requires drilling of the aquarium or the purchase of an aquarium with overflows built-in.

External Overflows

Requires the use of a siphon to go up and over the rim of the aquarium which is prone to breaking and leads to water overflowing onto the floor.

The main challenge with an overflow in reef tank plumbing is noise. Gurgling and sucking sounds can be difficult to stifle but there are 3 internal overflow designs that have proven successful.

Reef Tank Overflow Plumbing Diagram

Aquarium Overflow Types

Successful Internal Reef Tank Plumbing Overflow Designs

Durso – Internal Overflow

Utilizes a submerged inlet and an air tube or inlet to silence the noise. The air inlet frequently has a valve included adjusting the amount of air allowed to flow into the overflow.

Herbie – Internal Overflow

Utilizes a valve in the pipe to adjust the flow to match that of the return pump flow back into the aquarium. This produces a perfect siphon effect. This design also includes an emergency overflow in the event of a problem.

Bean Animal – Internal Overflow

Utilizes the Durso and Herbie designs to create a near-perfect solution that handles fluctuations in flow without creating noise. Additionally, the failsafe of the emergency standpipe for backup is a bonus.

Sump Reef Tank Plumbing

A sump is basically just an additional aquarium that is typically beneath your display tank. In an all-in-one aquarium, the back portion of the tank is blocked-off to utilize as the sump. There are many benefits to a sump with the only real downside being additional complexity and expense. The expense part really isn’t true though since you’d spend that money down the road dealing with issues that the sump solves.

Sump Benefits:

  • Maintains a constant water level in the display tank
  • Adds water volume which helps stabilize fluctuations in tank parameters
  • Creates a hidden place for equipment
  • Allows for larger equipment than hang-on-back (HOB) equipment

When plumbing in a sump you’ll typically want to have your return lines end below the water level. The only exception is the emergency return. It should be left above the water line so that it will be loud and help alert you to a problem.

Return lines down to your sump are typically PVC but can also be clear plastic tubing. If you go with the flexible clear tubing, be sure to get the braided type to help eliminate kinking.

Sumps use baffles to divide it into separate chambers with bubble traps in-between. A bubble trap is nothing more than 3 baffles. The first the water travels over. Next the water travels under the second. Then, with the third, the water travels over again. This is also done with just 2 baffles by simply omitting the third.

Some Sump Chamber Uses:

  • Filter socks
  • Protein Skimmer
  • Refugium
  • Live Sand
  • Extra Live Rock
  • Bio Media
  • Return Pump

You can purchase a ready-made sump or build your own. Many people build their own sump with a 40 gallon breeder tank. Glass dividers are best but you can use acrylic. Get reef-safe silicone sealant to adhere your baffles. Silicone adheres to glass with a death grip which is why it’s best to use glass baffles but if you don’t put much pressure on acrylic baffles it should work fine. Bath and Kitchen silicone sealant frequently has anti-bacteria additives which are a really bad idea for use in your sump.

Return Pumps

The return pump is what runs the entire setup. The return pump push water up the return line which in turn pushes water down the overflow. You’ll need get a pump powerful enough to turn over the volume of the main tank 10x per hour. You’ll also need to account for head pressure. Head pressure is additional pressure caused by the plumbing. This can be bends but can also be distance. For instance, some people place their sump in a basement room beneath their main aquarium. The return pump will need to deal with the added pressure of pumping water up several feet in that scenario.

An adjustable or controllable return pump is not required but a nice addition if you can afford it. In the Herbie and Bean Animal overflow designs a valve is included to adjust the amount of overflow to tune it to be silent. The valve adds additional head pressure to the system the pump has to overcome. With a controllable pump you can save some electricity and pump life by simply tuning the pump down in flow.

Return Line Reef Tank Plumbing

Display Tank Turnover

Obviously, we need a return pump to pump the water back up to the display tank. There are several options here but we need to start with how much water needs to be pumped per hour. Ideally, you want to pump 10 times the volume of your aquarium display volume every hour. If you have a 100-gallon tank you will want to pump 1000 gallons per hour. You will need to take into account head pressure so merely looking at the pump specifications and seeing that it pumps 1000 gallons per hour won’t work. For instance, I’m working on a new tank build where I will have my sump in my basement. There will be quite a bit of head pressure to overcome so I’ll obviously have to significantly step up in flow to deal with that hurdle.

Reactors, Protein Skimmers, and Other Equipment

Another consideration is that you will want to consider how to incorporate reactors, protein skimmers, and other equipment that may need to have water flow. You don’t have to use your return pump for this and you may not want to for various reasons. A smaller and dedicated pump or pumps for this task can work just fine.

Check Valves

Also, you will want to add a check valve to prevent water from flowing back down your return lines when the pumps are turned off or there is a power failure.

Diffusers/Return Jets

Last, you will need to add a diffuser to the outlet of the return line. Loc-Line is a great solution for this. You do not have to drill your tank for your return lines and simply have them go over the rim but drilling and using bulkheads ensure they’re secure and are much cleaner looking.

Putting It All Together

Typically PVC is used to plumb everything. Vinyl tubing is also used but is less ideal. Vinyl tubing can kink and cause an overflow. If you do decide to use vinyl tubing be sure to get the braided variety. It’s much less prone to kinking.

PVC plumbing is glued or chemically welded together. Once the piping is connected it will not come apart. Be sure to test fit your entire setup prior to gluing it together. Be sure to include unions in your plan. Unions will allow you to unscrew your plumbing wherever you include a union. This will allow you to perform maintenance. You should also include unions in areas you plan to change in the future.

In Conclusion

There’s a lot to consider when designing your reef tank plumbing setup. In the end you’ll have a very clean looking display tank that is free of dangling equipment. Not to mention you’ll be able to have more effective equipment.

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