While circulation pumps are almost always present in marine aquariums, they are often overlooked in freshwater tanks, despite having the potential to benefit a number of species commonly kept in the hobby. Many popular freshwater species live in fast-flowing river environments and tend to do better in aquariums when strong water currents are present. Bodies of water characterized by stronger water movement typically feature greater concentrations of dissolved oxygen: providing species native to these habitats with similar conditions in an aquarium will significantly benefit their long-term health.

The following are examples of freshwater fish that prefer strong water current:

  • Suckermouth catfish (Loricariidae)
  • Large species of widemouth catfish
  • Species of Anostomus
  • Species of Leporinus
  • Some species of Loaches
  • Many Central American Cichlids
  • Most Danios
  • Many Rainbowfish

During the 2013 Fluval Colombia expedition, fish were observed swimming in currents so strong that the members of the team had to hold on to avoid being blown away! Adult Leporinus yphorus were observed easily swimming in very strong currents at the head of large waterfalls. To learn more about our Colombia expedition, check out this video!

In marine aquariums, circulation pumps are almost always necessary. They are invaluable in preventing dead spots behind live rock structures, and of course for allowing strong water current to be directed at coral species that require it. Soft corals benefit from more gentle water flow to ensure their surfaces are kept free of accumulating waste, whereas hard corals prefer to grow in areas with very strong water movement.

When shopping for a circulation pump for your aquarium, we recommend considering the following:

  • Due to the fact that these pumps are submersed and functioning more or less all the time, it’s important that they are relatively low wattage. Operating multiple high power pumps can actually increase your aquarium’s water temperature.
  • The outer cage of the pump should support broad water flow patterns. Pumps that create too direct a current are not ideal: broad flow patterns are more natural and displace water more effectively.
  • The supporting base of the pump should allow for close to 180-degree articulation. If the goal is to improve oxygen levels in the aquarium, direct the output upwards, along the water surface, and position the pump to achieve strong surface movement across the length of the aquarium. This will help create a river-like effect at the surface.

Keeping your circulation pump operating efficiently is simple, requiring only the most basic of maintenance. The outer cage needs to be kept free of any debris – in the case of marine tanks, this includes coralline algae. Most importantly, the impeller assembly needs to be cleaned regularly – we recommend doing so once every month or two.

Fluval Sea CP circulation pumps have been designed to efficiently provide strong, reliable water movement for small and large aquariums alike. Their space saving size and innovative design minimizes tank intrusion, improves energy efficiency, and delivers a smooth, broad stream of ocean-like currents. They also feature oversized suction cups for secure and flexible mounting options anywhere in the aquarium! To learn more about CP circulation pumps, click here.