The return pump is the heart of a marine aquarium. It ensures proper skimmer operation, must consume minimal energy, and provide the required flow rate. Today, we have the Octo VarioS 2 in our hands, our next return pump. Let’s dive into our review.
article available also in: Italian.
The Octo VarioS 2 may not be the first choice that comes to mind for your marine aquarium’s return pump. However, we were intrigued by one key detail: its exceptionally low power consumption. This led us to choose it as our return pump, and before putting it into operation, we tested every aspect—consumption, flow rate, and head pressure.
In short, we found no weak points. Not only do its performance metrics match Octo’s claims, but we also discovered outstanding maintenance ease and record-low power consumption. We’ve never seen a pump with this level of efficiency. And the noise? Although we didn’t measure it, it is virtually inaudible. Keep reading to see all the data we recorded in our review.
The pump operates at 24V and is adjustable in five steps, making it suitable for a wide range of marine aquariums. We appreciated its color scheme but were less enthusiastic about the gray connectors—we would have preferred red to match the base and rear casing. The pump comes with two sets of hose adapters in different diameters. A crucial note: never use the smaller adapter! Read why in our article on saving energy in marine aquariums.
The Octo VarioS 2 is a centrifugal pump with an alternating current motor that operates at a low, adjustable voltage. As always, we measured head pressure, flow rate, and power consumption. For head pressure, we used our standard static method. For flow rate, we used the DigiFlow 6710M flow meter, and for power consumption, we relied on the RCE PM600.
Video Review of the Octo VarioS 2 Return Pump
Before diving into the technical data, check out our in-depth video review. We not only discuss the pump and its performance but also explain head pressure and the differences between technical and measured values. We provide guidance on sizing and demonstrate our testing procedures. It’s a must-watch! Use English subtitles if you need it.
Octo Varios 2 Technical Specifications
| European version 100-240 V 50/60 Hz DC 24 V | |
| Max Flow Rate: | 3.000 l/h |
| Max Power Consumption : | 25 watt |
| Max Head: | 4 metri |
| Lenght: | 8 cm |
| Width: | 13 cm |
| Height | 10,6 cm (solo corpo) |
| Official Price | 259,99 euro |
The Octo VarioS 2 boasts an impressive energy efficiency of 120 liters per watt and an economic efficiency of 11.5 liters per second per euro (though we’ll soon explain why the high price isn’t an issue). With a reference value of 6,000 l*m/h, this pump is suitable for most Italian aquariums.
At a premium price point, you’re investing in a solid, reliable pump that operates at low voltage, is dimmable across 5 steps, and comes with excellent baseline features. It also includes a float switch to automatically shut off the pump if the sump water level drops too low. While its energy efficiency is outstanding, its economic efficiency is lower—though this is negligible when you consider the long-term savings on energy consumption. Let’s dive into the lab results and see how it stacks up against other pumps we’ve tested (see page 3 for comparisons).
Construction
The pump features a simple, cylindrical design. The cap screws on and off by hand, making maintenance a breeze. In just a few seconds, you can open and close the pump without tools or worrying about screws corroding over time. Check out the video to see how quick and easy it is.
Inside the box, you’ll find the pump, two pairs of rubber mounts (of different diameters), and two PVC fittings for rigid piping setups. Important note: Never use the smaller rubber mount.
The impeller is modern, with 5 curved blades, which sets it apart from older pumps with similar flow rates. This design significantly improves efficiency.
Controlling the Octo VarioS 2
The pump’s flow rate and head pressure can be adjusted across 5 power steps. Using the integrated controller, you can set the flow rate and head pressure by increasing or decreasing the motor speed (remember, it’s a 24V motor). Additionally, there’s a button to pause the pump for 15 minutes (e.g., for feeding) or 60 minutes (e.g., during water changes)—a feature many overlook but one that’s incredibly convenient. The controller displays the settings via 5 blue LEDs, indicating modes from ECO to Normal and up to MAX.
The FS button activates the float switch, and the display shows its status.
The pump connects to the controller and power supply via a pair of connectors. Below, you can see the series of LEDs that light up as you switch between ECO and MAX modes.
For all our measurements, head over to page 2.
