# Culturing daphnia



## Lycosa (Oct 16, 2006)

I've done it before, but the problem comes in accidentally introducing predators and your culture is gone. I put fresh spinach/lettuce leaves/grass cuttings in a glass jar and keep it in the window until I have green water. Once I have a jar of green water, I add about 1/4 - 1/2 of it into the Daphnia culture. Carefully dump 1/4 - 1/2 of the water out of the Daphnia culture through an (fine mesh) aquarium net first. Flip the net inside out and dump the green water through the net to catch any 'chunks' in the water and to rinse off any Daphnia that got caught in the net while you were emptying water from the culture. I add more green water when the culture water clears. To start the culture, I just bought a Daphnia culture on e-bay. I kept the culture in a round clear plastic storage jar with a airstone running at the bottom of the jar 24/7.

I accidentally got some Hydra in my culture who bred out of control and ate my culture. Most likely because of the grass cuttings I used. (Still not sure how)

But.. rather than buy another culture I learned this:

You can get Daphnia out of a pond by holding a flashlight near the water at night. Daphnia will swarm by the hundreds in the light. Grab your aquarium net and you have a Daphnia culture. You might grab some other critters, but it is by far the easiest way to get a culture going and if the culture gets eaten by predators, get another culture for free.

One thing to note, Daphnia can multiply fast so you might find yourself needing 7 jars of greenwater going so you have available food at all times. Stop feeding the culture and it'll fade fast too.

I've kept an Infusoria culture going like that for over a year... super easy. :smile:


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## lainealex (Sep 27, 2009)

I have a pond: can I just go out each night with a flashlight and a net and a jar and scoop some daphnia up and then feed for 24 hours? 

Is there anything bad that could happen to my fish if I do this?

Thanks!

Lainey


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## Lycosa (Oct 16, 2006)

The only thing that could happen is if you get a parasite that hitchhikes into your tank with the daphnia and ends up harming your fish. I would have a hard time saying whether or not that would happen, but I can tell you that I had a culture going like that and I occasionally restocked it to freshen up the gene pool and I never noticed or had any problems with my fish because of it. Infusoria is great for your small fish and I'd like to think it's much better to give them something that allows them the use of their hunting instincts rather than the floating flake that falls slowly to the bottom. Besides, Daphnia rock for cleaning up diatoms in your tank.


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## lainealex (Sep 27, 2009)

OK, somehow I'm still not getting this. I make green water, I get a daphnia culture out of the pond, I add the daphnia to the green water, with an airstone in the bottom of the container - but then what happens? Do I have to add more green water? At what point do I have to add more?

Thanks for helping.

Lainey


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## Lycosa (Oct 16, 2006)

lainealex said:


> OK, somehow I'm still not getting this. I make green water, I get a daphnia culture out of the pond, I add the daphnia to the green water, with an airstone in the bottom of the container - but then what happens? Do I have to add more green water? At what point do I have to add more?
> 
> Thanks for helping.
> 
> Lainey


Ok, I'll try to make it a little more clear. Grab some tank water, or age some tap water by letting it sit so it can off-gas and stabilize the pH (no chlorine). Whatever water you use, make sure it is close in temp and pH of the water the daphnia come from. Treat the water the same way you would for your fish. Just make sure that they wouldn't get 'shocked' from largely differing water quality... the same way you would handle adding a fish to your tank.

Put that water into the container that you plan on raising the daphnia in, add an airstone, and grab some daphnia from the lake or buy a culture and add them to the container.

Dump some of the water out of the daphnia culture, fill the daphnia culture back up with some green water. Add more green water when the culture water is no longer tinted green. The daphnia eats the green diatoms in the water and turns it back to clear/not green tinted. If it is clear, then there is no food. 

Just feed the Daphnia whenever the water is no longer green. Use the net like I said in my original post and it should be easy to maintain. When you need some Daphnia to feed your fish, you can strain some through the aquarium net, pouring the water into another container and then dump the water back into the daphnia culture once you have enough in your net.

One last note: I figure my green water is 'green enough' when I am barely able or unable to see through the jar anymore.

Hope this helps


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## mubender (Mar 16, 2009)

i don't mess around too much with the green water (plus I'm too lazy to wait)...I get an empty water bottle and fill it 3/4 with cycled aquarium water, then i add a piece of dog food(science diet is what i have lying around), i add an algae wafer, and let it sit for about an hour. I then shake the bottle up, and use a dropper to feed the dog food/algae wafer mix to my daphnia cultures...so far in about 8 months of culturing i haven't had a crash (however i have noticed a few hydra in with the daphnia). i started with about 500 daphnia and now i have 8x5gallon buckets LOADED with daphnia. (by the way, Badis badis/Badis buxars/Pygmy sunfish love em) All my predator fish color up and spawn regularly.

Lots of ways to culture them, prolly green water is the best for them....but a little bacteria (dogfood/algae mix) is great for a pinch.


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## mistergreen (Dec 9, 2006)

here's my daphina thread
http://www.plantedtank.net/forums/s...es/94835-raising-daphnia-floating-plants.html

I used spirulina powder (health food store) and gluten free flour (grocery store) and a pinch of yeast. My population crash though. It might have gotten too cold in my basement over the winter. And I suspect excel is not good for them. I was treating my main tank with excel and used the water for my daphnia water change.


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## lainealex (Sep 27, 2009)

I understand perfectly now, thanks everyone!

One last question: how long does it take to make green water on the windowsill? 

Lainey


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## lainealex (Sep 27, 2009)

Also, do you need to cover the green water jar? Does it need an airline/airstone?

Lainey


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## mistergreen (Dec 9, 2006)

It'll take at least 2 weeks to have green water. It's good to have several containers going at the same time so you don't run out.

You want to leave it uncovered since they need O2. And an airstone is not necessary.


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## lainealex (Sep 27, 2009)

Are we talking about half gallon mason jars? Or just little cup size jars?

Lainey


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## zzyzx85 (Feb 13, 2008)

make as much green water as you can. I also have daphnia tub going in the back yard and I use a 10g with old aquarium water and an airpump in it making greenwater to "feed" the tub.


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## lainealex (Sep 27, 2009)

Is it likely I will get hydra from all this live food (I also feed baby brine and microworms and vinegar eels)?

If so, what does everyone do about hydra?


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## Lycosa (Oct 16, 2006)

lainealex said:


> Are we talking about half gallon mason jars? Or just little cup size jars?
> 
> Lainey


Mason jars work fine. I used the ones that have the plastic liner on the inside of the cap so it didn't rust the cap.



> Is it likely I will get hydra from all this live food (I also feed baby brine and microworms and vinegar eels)?
> 
> If so, what does everyone do about hydra?


I wouldn't say likely. I don't know how I ended up with it honestly. I 'suspect' it might have hitchhiked on some grass cuttings, but even that seems unreasonable. If you find hydra or some other predator munching on your Daphnia, remove some and start another culture. Honestly, I found it really easy to keep the culture going once I started it. Hydra, like Daphnia are visible to the naked eye so you can see the little anenome/octopus looking creatures in your culture if they get in there.


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## Craigthor (Sep 9, 2007)

I get Hydra in my main tank when I over feed fresh Brine Shrimp, but other tehn that I don't see them any wehre else. I keep 9- 1/2g Juice bottles of green water going. Once you get it made its easy to get it in constant supply. I feed nothing but live food to my tank though.

Craig


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## Franco (Jun 13, 2010)

I stick some washed lettuce in a 1.5 gallon glass wine jug (the really cheap stuff) with treated water and stick it by the window. After about a week it is really green. If I need green water in a hurry I put miracle gro house plant food in instead of lettuce so that the water is slightly blue. I get green water in about 2 days that way but it has higher nitrates so you cant overfeed it.

I go catch my daphnia in the wild at fishless ponds and swamps. I use 1 gal betta bowls or small plastic critter keeper tanks. I initially use the same water that I catch them in. Adding a little bit of baking soda and a few ice cubes to your capture container will keep them alive until you get home if you catch a ton of them.
Add daphnia, add food, throw in some aquatic plant clippings (duckweed is great too) to let them rest on at the surface and BAM, my population doubles in a week so I have to feed a few dozen a day to keep them in check.

I do daily water changes on the small containers that are heavily populated.

I have never had problems with little predators because I sort all of my catch as soon as i get home. Petri dish over white paper and a plastic pipette. Suck up all the daphnia, throw away worms, bugs, and copepods and rinse the daphnia in clean water a couple times to remove anything attached to them.

I suck them up with the pipette again to feed and rinse them again to keep green water algae and nitrates out of the tank/bowls I am feeding.

I do the same setup with ostracods (seed shrimp) except I feed either fish food or spirulina powder more heavily than the green water. These guys dont have a naupli stage either so they grow faster and seem to reproduce spontaneously.


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## Dave-H (Jul 29, 2010)

How exactly do you make the green water? I live in Colorado so I have plenty of sunshine but it gets really cold.


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## mistergreen (Dec 9, 2006)

clean aquarium water that's not treat with excel, meds etc..., decaying plant matter, and plenty of sun.


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