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Daphnia Culture for the Home Aquarius



Water fleas, Red mites are common names and (daphnia) is the real name. It is one of the great foods for Betta fish and fry. It is also considered one of the best by Thailand Betta breeders. They are smaller than a pinhead when born and are up to a half centimeter when adults. Because they have a jerky movement through the water hence the name water flea.



Daphnia reproduce most often by parthenogenicity, and bearing, on average, ten live young per individual during growing seasons.

During this time the entire race is made up of females. At the end of the growing season, and when the food becomes scarce the males will develop, and the females produce eggs that must be fertilized.

Interesting Fact

Did you know that waterfleas can change there behavior? If waterfleas smell fish, they hide themselves between water plants. But in the absence of fish they spread through out the water. They are attracted to light and in the dark they sink to the bottom. This is why you need to keep the bottom of you culture jars or tank free from rotting plant mater and food.


Cultivating is very simple and most people find success the first time. The best way to start is by placing a transparent bucket outside the house and add some blended old lettuce and a pinch of yeast and a spoon full of plant fertilizer to the water. Or you can use 15-15-15, urea, burnt sugar and rice powder at 1 tablespoon each for every 5 gallons needed to produce. Kits can help also if you want everything all mixed and ready to add.








Wait two weeks and when the water gets green, add some daphnia. This method is enough for the daphnia reproduction explosion to take place. When the water clears up and gets transparent again you can start the process all over again. To keep the culture going 24 x 7 all you need to do is keep adding food for the algae (fertilizer) and food for the daphnia (yeast and blended lettuce)











Growing Daphnia Tips

    1. You can grow daphnia in almost any type of container. We grow them in concrete vats in our fish house. If you need a lot of daphnia, it’s best to use a container that has a large surface area(a large plastic tub, 40 gallon aquarium or a kiddie swimming pool). If you don’t need a lot of daphnia, you can also raise them in a 1 gallon glass jar, 3 liter soda bottle or 10 gallon aquarium.
    2. Always age the water in your container before adding the live daphnia culture. Daphnia does not tolerate chlorine. It will usually die if you add tap water directly into your container when making water changes.

We age the replacement water for 10 to 14 days in the tubs above the daphnia vats.
The water will turn green with algae and provides some food for our daphnia when we do a water change.



What to Look Out For!

    1. The pH of the water can range from 6.2 to 8.9 . We usually keep the pH of our water at around 7.8.
    2. Change 20% of the water at least every 2 weeks. Remember to use aged water as your replacement water. You can even use your old aquarium water, when you do a water change, as replacement water. If your daphnia culture is not reproducing quickly and thriving, you might want to do more frequent water changes.
    3. The ideal temperature for growing daphnia is usually 72 to 85 degrees. When the water gets too warm, the daphnia culture will stop reproducing.
    4. The daphnia culture doesn’t need much oxygen to thrive. Containers kept outside with a large surface area don’t need any aeration at all. Containers kept inside should have very light aeration(just enough to break the water surface). Too much aeration(bubbles) can kill off your culture.



Why More Than One?

    1. It’s a good idea to have multiple containers of daphnia growing at the same time. Having a backup culture is great insurance if a daphnia culture goes bad and dies.
    2. Keep your daphnia containers in the sunshine. 6 to 8 hours of lighting is best. You must have a light on your daphnia for at least 10 hours if you grow them indoors. Placing their container in a sunny window is also a good idea as long as the water doesn’t get too hot.
    3. Daphnia will eat algae(green water), yeast and bacteria. We feed our daphnia yeast. We put yeast powder into a bucket with water and mix it. We then add enough of the yeast mixture to our daphnia container so that the water is slightly cloudy. The daphnia are filter feeders and will eat the yeast in the water. We feed the daphnia whenever the water becomes clear. Do not overfeed.

Live daphnia harvested from our vats.



How To Collect…..

  1. We use a fine net to catch our daphnia. It’s best to move the net in a slow figure 8 motion when trying to catch them. We then sift the daphnia through several different size strainers. The larger size daphnia is fed to the larger size discus. The smallest daphnia is fed to the tiny discus fry.
  2. Finding daphnia starter cultures should not be that difficult. Check the classified ads in tropical fish magazines or ask members at your local fish clubs or on tropical fish forums to supply you with some.
  3. It’s important to harvest your daphnia on a regular basis. Failure to do so can cause the culture to crash due to overcrowding.
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