The amazing reef aquarium of Bradley J. Syphus The amazing reef aquarium of Bradley J. Syphus


Water circulation is important for keeping fish, corals and even live rock healthy and thriving. We’ll explain the multiple benefits of water movement and how best to position submersible pumps in reef and marine aquariums. But first we need to describe the three types of submersible water pumps available to the marine aquarist.


Cobalt Aquatics MJ Pumps Cobalt Aquatics MJ Pumps



  • Basically a fully submersible water pump
  • Available in a variety of sizes and flow rates
  • Designed to create a narrow, high pressure blast like a power washer
  • Inexpensive


Maxspect Gyre Flow Pump Maxspect Gyre Flow Pump


Circulation Pumps

  • Purpose-built for increasing water movement in reef aquariums
  • Designed to move a large amount of water
  • Engineered to circulate water without the “power washer” effect


EcoTech Marine VorTech Pump EcoTech Marine VorTech Pump



  • Programmable flow rates and timing
  • Designed to recreate natural water surges and wave rhythms
  • Multiple circulation pumps can be programmed and automated
  • Costs more than powerheads


Increasing water movement in FO and FOWLR tanks

Fish-only and FOWLR (fish-only with live rock) tanks already have some water circulation from the filtration system, but If you see sludge building up behind decorations or at the base of live rock, you need more water movement! A simple powerhead, aimed either behind the rock or pointed at the front glass should stir up the debris, allowing it can be captured by the filter. Increasing circulation in the low-flow areas of the tank to keep things clean is very important as a build-up of organic sludge has been linked to increased disease and other problems.

Maximizing flow across the surface of your live rock is also important as live rock contains beneficial bacteria that break down fish waste and reduce nitrates through natural denitrification.  The Cobalt Aquatics MJ600 Multi-Purpose Powerhead is an inexpensive water circulation pump that has its own prefilter and adjustable hanger making it a great choice for most tanks that need a bit more flow. Another option is the Eheim 300 Compact Pump  as it has a tiny footprint but puts out an adjustable flow rate up to 80 GPH which is perfect for nano tanks.


Positioning pumps and wavemakers in reef tanks

Reef aquariums containing corals and other invertebrates need more specialized water movement. The biological balance of the tank is maintained by millions of bacteria living on and in the live rock. Pollutants in the water must be brought to the bacterial colonies in order to be broken down and water circulation is what carries these dissolved pollutants to the rock so the bacteria can work their magic.  Circulation is also critical for washing additional waste products away from corals as organic sediments can accumulate behind live rock, slowly decaying and polluting the water.

Natural reefs are continuously flushed with tides and waves, keeping the reef clean, well-fed and thriving. On the other hand, your aquarium will have some water flow from the filter system but that often will not be enough by itself.  Fortunately, we have special circulation pumps and wave-makers designed especially for reef aquariums that help to wash the waste away before it gets a chance to break down. Use circulation pumps to flush a target area with a gentle, high volume flow while making sure to position the pump without overwhelming the corals. The Hydor Koralia 3G Third Generation Circulation and Wave Pump is a great choice as it is designed for targeted water flow anywhere in the tank and the magnetic mounts allow for easy mounting and aiming.

For better control of the water flow pattern, use a wave maker like the Maxspect Gyre XF-230. The Gyre pump creates a massive horizontal flow pattern that evenly moves water throughout your reef.  The controller has five water movement modes and customizable flow cycles to give you a number of options. If using a single wavemaker, just position it to push water where it is needed. If you’re using multiple pumps to create opposing surges, position the water pumps so the surges complement each other.

The wireless Ecotech Marine VorTech series circulation pumps lets you target and control water flow anywhere in your aquarium. Whats really cool about the Vortech is that the pump motor sits outside the tank while the impeller and blades sit inside your tank being powered by the same magnet that holds it together.  This eliminates unsightly wires in the tank and greatly reduces motor heat transfer into the water. The wireless controller makes it easy to adjust the variety of flow characteristics until you find the settings that are just right for your reef.