How To Grow Daphnia For The Aquarium | Aquascape Addiction

How To Grow Daphnia For The Aquarium

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Daphnia are commonly used as a source of fish food, we look at what they are and a detailed step by step guide on how to grow them correctly for your aquarium.

How To Grow Daphnia For The Aquarium

You might have heard of daphnia before, especially when it comes to talk of feeding aquarium fish. Yes, they are used as food, but what are they really. We are here today to talk about what these little creatures are, why you might want to grow them at home, and what they are used for.

How to grow daphnia for the aquarium is the main point we are here to discuss right now but let’s first look at what Daphnia are and why you would considering growing them.

What Are Daphnia?

Daphnia are actually little creatures that you can barely see with your eyes. They are a small type of planktonic crustacean. In other words, daphnia are both crustaceans and plankton, some of the smallest crustaceans in the world. Daphnia are often referred to as common water fleas.

They range in length from 0.2 to 0.5 mm, so they are indeed very small. They are semi-transparent, which means they actually let some light through their bodies, making them even harder to see. They feature really prominent eyes with long antennas.

These creatures can be found in oceans all across the world and they serve as a big food source for small and big sea dwelling creatures alike.

Why Grow Daphnia?

There is really only one reason why you would grow daphnia at home. This is to feed your fish. Sure, you can feed your fish pellets and flakes, but those are not the healthiest fish foods, nor will your fish like them all that much.

Fish that eat meat love live foods, especially tasty little morsels like daphnia. Chasing daphnia around provides your fish with exercise, plus it lets them hunt just like they would in the wild.

There is also the fact that daphnia are packed to the brim with nutrients, something your fish will definitely appreciate.

Growing Daphnia – Step By Step Instructions

In all honesty, growing these things is not all that expensive, nor is it very hard. Yes, you do need to have the right equipment, but in the grand scheme of things, growing them en masse instead of buying them could save you a whole lot of money.

No, it is probably not worth growing daphnia if you only have a couple of fish to feed. However, if you have lots of hungry mouths in your aquarium, growing daphnia might just be the best solution.

That being said, you can also just grow a very small amount of them too. At any rate, let’s talk about how you can grow your own daphnia at home right now.

  • You need some kind of container. Large operations often use big concrete vats to grow massive amounts of daphnia, but that is probably not ideal for a home operation. Your best bet is to get a large container with a big surface area. Something like a plastic container, a kiddie pool, or even a 20 or 40 gallon aquarium will do just fine. If you don’t need a lot of daphnia, you can always use something smaller like a 5 or 10 gallon tank, or even just a glass soda bottle too.

  • Now you need to get daphnia culture. Daphnia culture is what will grow and develop into real life daphnia. Make sure to get your daphnia cultures from a reputable source such as your local high quality fish keeping store. However, you can find them online as well. Just make sure you get high quality cultures because how well the daphnia grow and develop will depend on it.

  • It is a good idea to have several containers on the go at once. This way, if one of the cultures does not work out, or one of the buckets dies off, at least you have more in reserve. We would recommend starting the cultures on different days (if you are doing multiple loads). This way you will have daphnia ready to harvest on multiple consecutive days.

  • Either way, now you need to add water to the buckets. Make sure to get a water softener and some kind of dechlorinator liquid. Daphnia cannot handle any amount of chlorine, so this is absolutely essential. They also don’t like hard water, so a softener is also crucial. If you add tap water directly to the cultures, they will surely die.

  • The good thing about daphnia is that they can handle varying pH levels. They have no problem growing in water that has a pH level between 6.2 and 8.9. As you can see, they can handle water on the more basic side of things better than water that is more acidic. Most people try to keep the water at a pH level between 7 and 7.9 (if you need help increasing your pH level then see this article and if you need to lower your pH level then this article will help) .

  • Daphnia cultures and growing daphnia don’t really need much oxygen, so you don’t need to worry about oxygen or aeration. As long as the water has a large surface area, this will not be a problem at all.

  • You need to have the right water temperature for the daphnia to grow and reproduce. They need the water they live in to be between 72 and 85 degrees Fahrenheit. If the water is any colder than 72 degrees, the daphnia will most likely die off, and any warmer than 85 degrees and they will stop reproducing. We would recommend getting a water heater and keeping the temperature at a steady 80 degrees.

  • Daphnia do like and need sunlight in order to develop, grow, and reproduce. If you have them outside, you should aim for between 6 and 8 hours of exposure to direct sunlight per day, which will work even if they are sitting in a window. If they are not getting real and direct sunlight, or in other words, if you are using artificial light sources, you should provide them with about 10 hours of light per day.

  • Daphnia, just like any other creatures out there, need to eat, so you need to feed them. They do like eating algae, which is convenient because algae is likely to develop in daphnia tanks with lots of light anyway. However, you will probably need to feed them anyway. The best food for daphnia is yeast. They are filter feeders and will absorb the yeast directly from the water.

  • You should change about 20% of the water in the daphnia tank every 2 weeks. While they do not require filtration, they will benefit from regular water changes. If you find that your daphnia are not reproducing fast enough, you might want to change more water more often.

  • Use a fine fish net to harvest the daphnia, using a figure 8 pattern to catch them. Make sure to harvest the daphnia fairly often because the overcrowding of them can lead to the total crash of the culture. If you fins that you have too much, you can always freeze dry the daphnia and save them for later days.


As you can see, growing daphnia for fish food is not very hard, expensive, or time consuming. Yes, you do have to do it the right way, but as long as you follow the tips we have outlined above, you should have a permanent and never ending supply of very nutritious food for your fish.