If you’re using an aquarium, a ten gallon tank works best. [2] X Research source Here’s a cool hack: divide the tank into two halves using a piece of plexiglass, creating two separate cultures. Now, you have a backup in case one culture fails![3] X Research source
If you’re using a small container, drill a hole into the lid to allow the the tubing to pass through.
It’s best to keep your culturing container at the same salinity as your main tank. That way, when you feed your copepods to your fish or coral, the copepods won’t go into shock. [7] X Research source
Nannochloropsis is a common phytoplankton that’s pretty easy to find.
You may be tempted to clean up the “gunk” that collects at the bottom of your tank, but leave it until you do your monthly cleaning. It’s completely normal, and actually healthy for copepods![10] X Research source
Don’t worry too much about acclimation. These guys are tough!
Wait a week in between harvests to allow the adult population to regrow.
If you’re using a tank, you should change the water every four weeks. Change the water weekly for a small culturing container, like a jar or a large cup.
An in-tank refugium is the simplest and cheapest type. It’s a small container that allows water to flow through but keeps bigger critters, like fish, out. A hang-on refugium is a separate container that hangs off the back of the main tank, while a sump-based refugium is a second tank that is placed under your main tank.
Don’t overclean your refugium–leave algae and detritus so your copepods can graze. [17] X Research source You should trim your macroalgae occasionally to prevent overgrowth. [18] X Research source
If removing predators is too difficult or you simply don’t want to, raise your copepods in a separate container.
To see how many copepods are in your tank, shine a light in your tank at night. The copepods will look like tiny white specks swimming towards the light. You may also be able to find these little critters behind live rock or collected in tank corners.
Tigriopus californicus is one of the most common species of copepods, and should be used to feed adult fish. These critters are pretty hardy and can survive at high population densities and varying water temperatures. Because Tigriopus are a larger species, they should never be used to feed fish larva. They can claw at the larva, causing distress and death. Tisbe and Nitokra are best for feeding coral and other filter feeders. They reproduce more quickly than Tigriopus and are smaller, which might make them a little harder to see. Like Tigriopus, they are tough.
If this happens, you’ll need to select a smaller species of copepod.
