Daphnia culture

[saiwong]

Hello,

I've made a few attempts at a Daphnia culture. The longest I've had them survive is about a month. I don't know why my culture are dying. Last time my culture was going fine but had some noisy diy work that needed to be done in same room. So I relocated my Daphnia to another room. This room didn't have same level of sunlight but thought relocation was only for afew hours so it should be ok. After I returned Daphnia back to original room after diy work was completed about only 10% seemed to have survived?

I am going to try one more time but this time I am thinking of using green water instead of yeast. Am I correct I just use aquarium tank water and leave container by window for it to turn green?

Also how often do you water change and at what percentage. Is 50% water change too much?

 

[Caliban07]

Are you using tap water? I would use RO water to start the culture then harden it slightly and add some Indian almond leaves etc.

daphnia don’t do well in dechlorinated tap water in my experience.

 

[saiwong]

I am using water from my main aquarium (water change) and yes it was originally declorinated tap water. I will look into getting those leaves.

Do you feed with yeast , green water or something else?

 

[Caliban07]

A friend of mine uses warm liquid yeast

 

[Colin_T]

Daphnia are best kept in green water because it's easier to keep clean compared to adding yeast to the water. You can also feed them infusoria. Don't wase your time adding a few leaves, if you want infusoria, you need lots of rotting plant matter and the daphnia can't be in it while it's brewing/ growing.

You can do a 50% water change just make sure you use dechlorinated water. Don't use dirty aquarium water because any ammonia, nitrite or nitrate can kill the daphnia, as can medications.

If the water is too warm, they produce eggs and the adults die. If you let the sediment in the bottom of the container dry out for a few months, then add some clean water, you can usually start another culture form the dormant eggs.

See the following link for information on culturing live foods for baby fish. This includes green water, infusoria and daphnia. If you live in a warm climate either culture daphnia during the cooler months or get Moina. They tolerate warmer water better.
https://www.aquariumadvice.com/forums/f82/back-to-basics-when-breeding-fish-380381.html#post3578561

 

[saiwong]

Has anyone tried feeding smashed up algae wafer to Daphnia?

 

[Colin_T]

algae wafers and other fish food simply create ammonia and kill the daphnia

 

[Caliban07]

Has anyone tried feeding smashed up algae wafer to Daphnia?

Use yeast or green water the food will cause ammonia as Colin says. Daphnia Magna are also extremely sensitive to heavy metals and as such are used in bio assays for evaluation of heavy metal toxicity in natural waters. I personally wouldn’t recommend using city water to culture them. Use some rain water or bottled spring water.