Step-by-step
Step 1: Set up culture container2-5 gallon container or unused aquarium. Aged dechlorinated water at 65-72°F. Light source 8-10 hours/day.
Step 2: Inoculate with starterAdd 1-2 cups of live daphnia starter from a hobby breeder or local fishkeeper. Order online (Aquatic Foods, Carolina Biological).
Step 3: Feed 1-2x weeklyTiny pinch of active dry yeast dissolved in water. OR live phytoplankton (Phyto-Feast, Reef Nutrition). Water becomes slightly cloudy, then clears as daphnia eat.
Step 4: Wait 7-10 days for population boomDaphnia reproduce parthenogenetically (no males needed). One female produces 80-100 offspring per cycle.
Step 5: Harvest with brine netSkim daphnia off the surface or scoop from clear water. Rinse in fresh water before feeding to display tank.
Step 6: Maintain cultureNever harvest more than 30% at one time. Add fresh aged water as it evaporates. Resist aerating too vigorously - daphnia are damaged by strong air bubbles.
FAQ
Why did my daphnia culture crash?
Most common: overfeeding (rotting yeast pollutes water), too-strong aeration, bacterial bloom, or temperature spike. Restart with a fresh culture and reduce feeding.
Can daphnia live in my display tank?
They'll be eaten within minutes by most fish. Daphnia are a feeding treat, not a permanent tankmate.
How much daphnia to harvest per fish?
A scoop the size of a dime feeds 1-2 small fish. Adjust based on appetite + tank size.