The Salty Side: Saltwater Aquariums for Beginners

Return Pump For Saltwater Aquariums

Return pumps are integral to any marine system. They help to move water from the sump or rear filter chamber, back into the display. Your sump or rear filtration plays a huge role in the ultimate success of your tank. It is where you keep your filtration (both mechanical and biological), and your heating out of sight. Your return pump connects your sump to your main display and is one component of your system which should not be skimped on. We look at what exactly a return pump for saltwater aquariums are, and which you should choose.

CURRENT USA eFlux DC Flow Pump with Control 1050 GPH | Loop Controllable Aquarium DC Return 210-1050 GPH | Quiet, Submersible or External | Fish Tank, Sump, Pond, Freshwater and Saltwater Marine Use
  • ADJUSTABLE FLOW- Unlike traditional AC water pumps, eFlux flow pumps are DC powered and completely controllable. Simply turn the dial to adjust the flow until the optimal flow rate is reached.
  • SUBMERISBLE or EXTERNAL- Safe for saltwater or freshwater systems, eFlux DC flow pumps can be installed submersible or external (inline). Quick couple hose barb fittings are included to make installation and servicing easy.
  • INCREDIBLY EASY- A cinch to install, eFlux Flow pumps have a very small footprint, allowing them to fit into even smaller sumps and tight spaces. High flow combined with high pressure makes them the perfect choice for return pump applications.

What is a return pump?

Every marine system includes a form of filtration which is separate from the main display. It could be a sump, rear filtration chambers or even an external sump. A return pump facilitates the movement of water from the display through the filtration, and back into the display again. They ensure that your water is systematically and repeatedly filtered day in and day out, keeping your tank as clean and healthy as possible for your inhabitants.

If a return pump for saltwater aquarium fails to work, invariably this means that you are no longer heating your tank (unless you physically move the heater into the main display), and that your tank no longer has any form of mechanical filtration.

Return pipe size and calculation

The suggested turnover rate of a return pump is often 5x – 10x that of your systems water volume.  However aiming for a lower end of the turnover rate, 5x – 7x, is better for the filtration process, resulting it cleaner, clearer water.

Why?  Well, if water is being pumped too quickly, the amount of time being spent passing through the skimmer, reactors and UV sterilizer, if installed, may not be long enough for the water to be filtered effectively.  By reducing the flow, it will enable the water contact time to be extended, thereby ensuring more of the water is filtered more thoroughly at each passing.

Most return pump for saltwater aquariums are produced as controllable DC.  This is handy because it allows the reefer to purchase one at the top end of the gph range, but you have the ability to dial it down with the controller to your desired flow rate. 

Aquarium Size (Gallons)

Recommended Turnover Rate of 5x - 10x (Gph)

Return Pump Options/Example

How to plumb a return pump for saltwater aquariums

There are two methods of plumbing a return pump in. You can either hard plumb it in, or you can use flexible hose/tubing:

Hard plumbing

This method is achieved by purchasing and installing plastic pipework (the same you would buy for plumbing your bathroom), using solvent weld as the fixative, and planning the route the water will take. Invariably if you are going to the expense of installing hard plumbing you would also consider two or more connections.  One connection for reactors and possibly, a UV steriliser.

Of course this means that the system will also need integrated gate valves to ensure the correct flow is achieved through each item.  It is worth remembering that if multiple items are being fed from the same return pump then the result will be a lesser flow to the tank.

Flexible Hose

This is by far the most popular, purely based on the cost.

It is advisable to install silicone hose, instead of aquarium type green or transparent hose.  Over time aquarium hose can become harder, making the possibility of them slipping off a barbed end connection more likely.

TetraPond Pond Tubing, 1/2-Inch by 15-Feet
  • Connects to pumps, bio-filters, UV clarifiers, waterfall filters and other water features
  • Will not crimp or collapse
  • Can be buried to conceal

Best quiet return pump for a saltwater aquariums

As already stated, a return pump should not be skimped on. The more you spend on a quality pump, the more satisfied you will be in it’s performance.  A good return pump should not be noisy and there are actually quite a few that are known to be extremely quiet.  So much so that’s it’s virtually impossible to say which one is best.   

Any return pump will be noisy if it ends up against another object. The trick is keeping it away from anything that will produce vibration and noise.   

What is return pump head height?

This is simply the distance from the pump to the outlet in your tank, and shouldn’t have a massive impact on your decision making if you are adding it to a standardised marine system. However, if you are planning on running your sump in the basement and your display on the ground floor, this becomes quite important.

Make sure you purchase a known make with a warranty and easily available replacement parts. You never know when a snail will snag the impeller!

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