How to Culture Copepods

Copepods are one of the most valuable live foods in a reef aquarium. They're packed with nutrients, perfect for finicky fish and fry, and help clean up detritus and microalgae as they go. Best of all, they're surprisingly easy to culture at home once you've got the basics dialled in.

What you'll need

1. A clean container (2 to 10 L works for most home cultures)
2. Saltwater at 1.020 to 1.025 salinity
3. Live phytoplankton as the food source
4. A starter culture of copepods
5. Gentle aeration (air stone or airlift)
6. Salinity and ammonia test kits
7. Thermometer

Step by step

1. Set up the tank. Fill your container with clean saltwater and add an air stone or airlift. Avoid aggressive flow. Copepods prefer calm water.

2. Add phytoplankton. Dose live phytoplankton daily, enough to keep the water lightly tinted green. The phyto feeds the pods and helps maintain water quality between water changes.

3. Introduce the copepods. Pour in your starter culture. Tisbe, Apocyclops, and Tigriopus are popular choices, each suited to different goals (reef refugium, small-mouth fish food, broodstock support).

4. Harvest slowly. Wait 5 to 7 days before your first harvest, longer if your starter was small. Use a fine mesh sieve or turkey baster to collect pods. Always leave plenty behind to repopulate the culture.

5. Maintain. Top up evaporated water with fresh RODI. Feed phyto consistently. Don't overharvest, and don't let water quality slip. Both will crash the culture quickly.

Pro tips

1. Run two cultures. Split into two containers so a single crash doesn't end your supply.
2. Keep temperatures stable. 18 to 26°C suits most species. Sudden swings hurt reproduction.
3. Don't let them starve. Copepods need fresh phytoplankton daily. If the water is clear, they're hungry.
4. Watch ammonia. A weekly 50% water change keeps waste under control and avoids ammonia spikes that can wipe a culture out overnight.

Start your own culture

You'll need both a starter culture of copepods and a steady supply of live phytoplankton to feed them. Get those two right and the rest is patience.