# daphnia-safe fish and shrimp?



## NatalieT (Mar 20, 2007)

I know, I know, there aren't supposed to be any things that are "safe" to keep with daphnia. Daphnia get raised with green water, maybe snails, and nothing else.

So why are there still so many daphnia swimming happily around my tank right now? It's been 6 hours, and I didn't add very many daphnia to start with! (Siphoned 1/2 cup of water from one culture and dumped it in) The tank inhabitants are:
panda cories (2)
pygmy cories (5?)
ghost shrimp (6?)
cherry shrimp (dozens?)

Are these really "daphnia-safe," or do I just have weird specimens of them?

Natalie


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## southerndesert (Oct 14, 2007)

Should be fine I would think.... Ottos are OK as well. They (Cories and Ottos) are not designed to hunt down live critters, but if one is hapless enough to end up in their mouth it's history....

Bill


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## newbie314 (Mar 2, 2007)

I have glo-light tetras, and I'm pretty sure I have daphnia and definately cyclops.
They seem to swim around. Maybe just too many for them to catch.
I have a planted natural aquarium, light and heater so the still water is great for these types of pond creatures


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## chikorita (Dec 20, 2007)

I do culture daphnia all by themselves in a 18g bucket .. They dont like new water .. so if you change the tank water .. some of them might die .. My daphnia water is like 6 months old and I dont change water on them at all .. I feed them with yeast on a daily basic


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## NatalieT (Mar 20, 2007)

chikorita said:


> I do culture daphnia all by themselves in a 18g bucket .. They dont like new water .. so if you change the tank water .. some of them might die .. My daphnia water is like 6 months old and I dont change water on them at all .. I feed them with yeast on a daily basic


Thanks for the warning, but that won't happen here. I never do water changes, because EVERYTHING might die. The water that comes out of my pipes has too much copper (killed fish before I figured it out!), so I only add water to replace evaporation. I de-copper the new water by letting it soak a few days in a bucket with a packet of Seachem Cuprisorb--so far, the fish/shrimp/daphnia are alright with this. (I've had the daphnia for a month or so now, its just the first time I tried putting some in this tank.)

The daphnia are eating greenwater siphoned out of my other tank (lots of guppies/platies/cories). My daphnia are primarily for the sake of controlling greenwater, although of course I feed extras to the fish too. If I ever run completely out of greenwater, I'll probably just feed the last of the daphnia to the fish and be done 

Natalie


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## NatalieT (Mar 20, 2007)

southerndesert said:


> Should be fine I would think.... Ottos are OK as well. They (Cories and Ottos) are not designed to hunt down live critters, but if one is hapless enough to end up in their mouth it's history....
> 
> Bill


That is what I would have thought, but then I'd read reports of people feeding baby cories on baby brine shrimp; and I've seen people's accounts of cories that ate daphnia; so I started to assume that they could hunt, after all.
This thread, for example: http://www.aquaticplantcentral.com/...37787-will-corys-commit-daphnia-genocide.html has several accounts of daphnia-eating cories, but no accounts of daphnia-ignoring cories.

I just looked in my tank for the first time this morning, and I don't see many daphnia left; so either the cories decided to hunt by night, or most of the daphnia died of something else  Darn, now I want to figure this out; I guess its time for a few temporary nanos--all filled with water from the same tank and with similar plants, 1 cory or 1 shrimp or none, daphnia in all of them. Then see where the daphnia multiply or decrease 

Natalie


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## newbie314 (Mar 2, 2007)

Natalie, sounds like you might be a good candidate for an el-natural aquarium.
I have no circulation. Like a pond but with no real algae problems.


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## NatalieT (Mar 20, 2007)

newbie314 said:


> Natalie, sounds like you might be a good candidate for an el-natural aquarium.
> I have no circulation. Like a pond but with no real algae problems.


That's basically what I've got! There's actually 2 aquariums, but they're pretty similar. One has gravel, one has dirt with a little sand on top. Both have lights, a screen cover, water, and lots of healthy plants/fish/inverts. Nothing else. No filter, no heater, no bubbler, no co2, no fertilizer, no added nutrients, no water changes, etc. I feed the fish most days (once a day); I add water when it gets low. One tank has had greenwater for about 6 months, but the daphnia are helping now. (I waited a few months to see if it would resolve itself, but it didn't). I'm a lazy, procrastinating cheapskate who likes to watch experiments happen--this kind of tank suits me quite well  Little to do, little to buy, usually something happening to watch


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## chikorita (Dec 20, 2007)

all fishs would eat daphnia ..
I culture daphnia just so that I have livefood once a week for the fishs


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## NatalieT (Mar 20, 2007)

Update: it now seems sure that my pygmy cories and my cherry shrimp do not hunt daphnia. I did a major tank overhaul, and set up two single-species compartments separated by a tank divider: pygmy cories are on one side, cherry shrimp on the other. The daphnia appear to pass freely through the divider and are equally numerous in both sections. It has now been this way for a full week, so I'm pretty sure it'll continue that way. During that week, I've seen baby daphnia grow progressively to full size, so it's not just a matter of the big ones being too big to eat--the small ones are OK too.

I still don't know whether the panda cories and the ghost shrimp eat daphnia, because I put them in my community tank, where daphnia have no chance anyway.

Natalie


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