Copepods & Amphipods are a crucial part of the ecosystem within your aquarium. They provide food for fish & corals, and because these tiny crustaceans feed on microalgae, they become rich with its fatty acids. Copepods provide a steady source of essential fatty acids for corals, invertebrates and fish. They are absolutely essential if you plan on housing a mandarin goby, or other types of Dragonets, the renowned fussy eaters live entirely on a diet of Copepods & Amphipods.

How do I add Copepods into my fish tank?

Simple. You add them yourself.

If you started with live rock, the chances are that you already have a few in your tank. They can come in on coral frags too, but if you dip your corals, they will be killed during the dipping process.

The few that do manage to hitch-hike their way into your tank, are not nearly enough to support your tank. Some will die off, the majority of them will be consumed by your fish & corals.

To maintain a steady population of Copepods within your aquarium, there are a couple of things you can do.

  • Buy packets of Copepods to add to your tank. For about £1.50 per packet, you can buy Copepods ready to go straight into your tank. Simply wait for the lights to turn out, turn off the flow & pour them in. I was using around 3 packets per week in my 180 gallon display tank.
  • Add a refugium to your aquarium. This will provide a “safe-space” for your Copepods to live and breed. Some of them will drift through your sump and into your return pump, in-turn feeding your tank.
  • Build your own Copepod culturing station.

Building a simple Copepod harvesting station on a budget

What you will need:

  • Three large plastic jars/containers
  • An air pump
  • Air line (2 metres)
  • Three non-return valves
  • Three Air-stones
  • Three air line adjusters
  • Air line splitters (if your air pump doesn’t have multiple spare outlets)
  • Starter culture of Phytoplankton
  • Starter culture of Copepods
  • F2 fertiliser

If you shop around, there are good deals to be had with all of these items. I bought my air pump, air line, non-return valves and airstones from All Pond Solutions in one bundle for £17.99 (Jan 2020). The air pump has 4 outlets, so I can add another culture at a later date if required.

Air Pump from All Pond Solutions
Air Pump from All Pond Solutions

My containers were £11.99 from eBay, they are 3000ml plastic jars. My starter cultures were two packets of £1.50 copepods (£3.00 total) and 250ml of Phytoplankton at a cost of £4.99. To enhance the growth of the Phytoplankton I use F2 fertiliser, which costs £4.99 for 200ml. The Phyto, F2 and Copepods were both bought from eBay.

Total spend = £32.96

Setting up a Copepod culturing station

Step one – Drill one hole in the top of each of your plastic jars. The hole should be a tiny bit bigger than your air line.

Step two – Place your pump & jars where you plan to keep them. It is advisable not to keep your Copepods in direct sunlight, this is due to the fluctuations within the temperature which can be caused by direct sunlight. However, I personally keep mine in a window as I don’t want to have to add lights to the Phytoplankton culture. I have seen no ill-effects from keeping them in the sunlight. I have also provided them with plenty of hiding spaces, which ensures they can be active throughout the day, feeling secure with somewhere to hide if required.

Step three – Cut three pieces of air line tubing to suit the depths of your jars. This doesn’t need to be overly accurate, just cut them long enough to ensure you can put control valve at the top, outside of the jar, and that the air stone will reach the bottom of the jar.

DIY Copepod Culture
DIY Copepod Culture

Step four – Attach an air stone to one end of the piece of air line you have just cut. Feed the other end of the airline through the lid & attach an air regulator to it. Do this for all three of the jars.

Step five – cut three small length of air line (about 10cm in length) and attach a non return valve to each of them. Be sure to check that your non return valve is the right way around! You want to be able to blow air through the short piece of tube, if you can’t blow through it, you have it the wrong way around. Attach the other end of the short air hose sections to your air pump or airline splitter. If you have an air line splitter, add a short section of air line from your pump to your splitter.

Step six – Measure out three pieces of airline that are long enough to connect each of your jars to your three non-return valves. Try to leave enough air line that they lines aren’t tight, it will allow you to move the cultures more easily, without fear of pulling them all to pieces.

Step seven – Fill two of the jars with used aquarium water. Add one packet of copepods to each of the jars, more if you would like to see faster results.

Step eight – Add the Phytoplankton culture to the third jar, then add roughly double the amount of phyto of used aquarium water to the third jar. So if you have 250ml of Phyto, add 500ml of aquarium water. When the phyto culture turns a dark green (normally after a couple of weeks), you can then add double the water volume again. Add one drop of F2 fertiliser to the phytoplankton culter each week.

Step nine – Turn on the airpump. Use the adjusters to reduce the amount of air in the copepod cultures to a few small bubbles each second. The Phyto needs to be turned around a lot, so keep as much air going through that as you possibly can.

Step ten – Sit back and let them breed! Just add a bit of phyto to your copepod cultures to keep a slightly green tinge to your water, and start harvesting once your have a decent population of them. I now take a glass full of water out of my culture every 3 days, and replace the water with fresh tank water. I have started putting Phyto into the tank too, the corals and filter feeders love it!