Daphnia, commonly known as water fleas, are an excellent food source for juvenile and adult fish. They are easy to culture and take very little maintenance to keep a colony going. Harvesting is very simple as well as they are a fully aquatic live food, which means you don’t have to clean up if you accidentally overfeed as you would with other live foods like grindal worms.
If you have a planted tank that you have a lot of leftover trimmings from that you don’t sell or just leftover vegetables like lettuce, then this is probably perfect live culture for you.
This guide on culturing live Daphnia is a guest post by Jesse from Aquatic Mag!
Building Daphnia Colony
With this method, you want to make sure you have a spot for multiple 5+ gallon size buckets that will get enough sunlight (typically in the morning or afternoon). Once you’ve found a spot, you’ll need one or multiple buckets with lids. After this, you are all set to culture live Daphnia!
How to build outdoor bucket for daphnia
For the bucket lid, cut two large enough holes with a utility knife to ensure ventilation. Then glue some thin mesh like mosquito netting over the holes to keep any bugs or debris out that you don’t want in. You will also want to punch a singular hole through the bucket lid to run an airline down into the water to provide important aeration inside the water column which the Daphnia thrive on.
Once done, you can now add de-chlorinated water as well as plant matter that you are willing to let decay. You can experiment with what plants you want to leave in there – typically aquatic plants or lettuce works but if you have something else in stockade, try it!
After a few days, you can then seed the culture (you can purchase daphnia here). This will get you started and once you have a colony growing, you can transfer them over to another bucket for more productivity and security in case one bucket crashes.
Harvesting Daphnia is as easy as putting a fish net in there and picking them out. They are slow jerky swimmers, so pulling out a good daphnia count is pretty simple with one swoosh.
You should be able to harvest from your daphnia culture almost every day without affecting the population – especially with 2+ buckets running. Of course, bigger aquariums or larger stocking of fish will need more food – so scale to your needs.
Discus fish like the video below are fed daily daphnia from juvenile to adult stages from fish farmers.
Daphnia Food Recipe
So what do the Daphnia eat? Well they are filter feeders, so besides the green water that comes from decaying plant matter, aeration, and sunlight – You want to try to feed them something supplemental that will give enough nutrients and protein; because of course your fish are going to eat them and that’s what they need. I found using a mixture of 1-part Dry Yeast/Soy Flour and 1-part Spirulina Powder works awesome but you can always experiment.
- Dry yeast (or) Soy Flour
- Spirulina powder
- High in protein
If you have any more questions about setting up your own Daphnia colony or want to share your own tips and tricks, be sure to leave a comment below. Happy fishkeeping!
Cover photo: Vannlopper (Daphnia magna) by NTNU