• You are viewing the forum as a Guest, please login (you can use your Facebook, Twitter, Google or Microsoft account to login) or register using this link: Log in or Sign Up

Feeding daphnia with crushed fish flakes

tiger15

Member
Joined
14 Mar 2018
Messages
892
Location
USA
I am feeding live daphnia to my newly hatched fish fry, but the daphnia are too large for the fry. So I hope the daphnia can give birth to babies tiny enough for the fish fry to eat. I’m crushing fish flakes to feed the fish fry and wonder whether daphnia will also consume and thereby multiply with babies.
 
Adult Daphnia are to big for most of my fish so one method is I use a turkey baster with two different size nets ,the first net catches the large ones the smaller ones go through ,and I've also bought some Monia which are much smaller perfect for Chilli's ,cpd and Medaka fry, my cultures crashed pretty quick when I was feeding them yeast , you need green water,you can buy a small bottle starter culture of ebay or make your own fill a bottle with water put a big pinch of that old flake food in and leave a desk lamp over it for 24 hours a day and it will turn green in around two weeks maybe sooner, stir it once a day for gas exchange
 
Adult Daphnia are to big for most of my fish so one method is I use a turkey baster with two different size nets ,the first net catches the large ones the smaller ones go through ,and I've also bought some Monia which are much smaller perfect for Chilli's ,cpd and Medaka fry, my cultures crashed pretty quick when I was feeding them yeast , you need green water,you can buy a small bottle starter culture of ebay or make your own fill a bottle with water put a big pinch of that old flake food in and leave a desk lamp over it for 24 hours a day and it will turn green in around two weeks maybe sooner, stir it once a day for gas exchange
Certainly, the best way to feed daphnia is to cultivate green water with strong light. Daphnia is filter feeder that thrives on live yeast, live bacteria (bacterial bloom), live infusoria or live Euglena (green water). But my fry tank has no strong light and it takes time to cultivate live foods for daphnia. Ideally, I’m wondering if I can find non live food such as crushed flake, milk or anything readily available to feed the daphnia so they can thrive and make babies.
 
Hi all,
Certainly, the best way to feed daphnia is to cultivate green water with strong light. Daphnia is filter feeder......
You can use spirulina powder, you only need a tiny amount dissolved in some tank water.
They filter particles by size, so anything the "algae" sized is ingested. Spirulina powder is a good one
I’m wondering if I can find non live food such as crushed flake, milk or anything readily available to feed the daphnia so they can thrive and make babies.
If you add some hay it will keep the culture ticking over. I'd definitely avoid milk (and yeast), but paprika and gram flour (chickpea) work quite well.

Cheers Darrel
 
You can use spirulina powder, you only need a tiny amount dissolved in some tank water.

They filter particles by size, so anything the "algae" sized is ingested. Spirulina powder is a good one.

If you add some hay it will keep the culture ticking over. I'd definitely avoid milk (and yeast), but paprika and gram flour (chickpea) work quite well.

Cheers Darrel
Spirulina powder sounds good. Spirulina is an ingredient of quality fish food, so it’s food for both fry and daphnia. Not sure why yeast, commonly recommended, is no good. I tried baker yeast before and can confirm that it didn’t work. Adult daphnia are too large for newly hatched fry, and without food and strong light, the daphnia will die off after a few days. I will experiment with spirulina, along with flour since I already have it in my kitchen.
 
Hi all,
..... Not sure why yeast, commonly recommended, is no good. I tried baker yeast before and can confirm that it didn’t work.
I think the problem is that to get enough yeast cells in the water to feed the Daphnia, you are balanced right on the edge of tipping over into polluted conditions, which then kills them off.

Yeast can give you short term boom, but in my experience, always shortly followed by bust.

Cheers Darrel
 
Hi all,

I think the problem is that to get enough yeast cells in the water to feed the Daphnia, you are balanced right on the edge of tipping over into polluted conditions, which then kills them off.

Yeast can give you short term boom, but in my experience, always shortly followed by bust.

Cheers Darrel
Yes, it's difficult to know the right dosage to provide adequate food versus pollution. Yeast is not cheap either. I once dosed it to sugar water to generate CO2 but gave up shortly in favor of CO2 tank.

BTW, can sugar water be used in lieu of flour to feed daphnia, both are carbohydrate that can lead to bacterial bloom. Daphnia is known to be great in clearing bacterial and green water bloom. I guess it's , hard to balance the right dosage.
 
Hi all,
Yeast is not cheap either. I once dosed it to sugar water to generate CO2
I would always "grow my own", rather than using dry powdered yeast, straight from the packet.
BTW, can sugar water be used in lieu of flour to feed daphnia, both are carbohydrate that can lead to bacterial bloom.
The problem with sugars (mono and di-saccharides) is that they are among the <"low hanging fruit of microbial substrates">. I think that is why adding a small amount of hay works <"Results from experimentation with Daphnia Cultures- Alternate Feeding">, you get more of a trickle of substrates for micro-organisms and that damps down "boom and bust" - <"Culturing daphnia">.

cheers Darrel
 
Last edited:
I've been finding it really easy to culture green water for my daphnia tubs - just a clear tub (60 litre in my case) in a South facing spot in full sun all day. Initially seeded with some chlorella, fill with tap water and add a cap full of the BioBizz Fishmix that @louis_last recommended in the other thread, and its dark green within a week or two. I use a solar powered pond airstone too to try and help keep the algae in suspension. Though the daphnia/moina that I have in the tubs happily eat it off the bottom of their tubs too if it settles out once added to the breeding tub.

Once the culture water is dark green I transfer it to the various daphnia tubs, leaving about 5 litres in the green water tub, and then just refill with tap water and a cap of Fish mix, and off it goes again - rinse and repeat each time.
 
Back
Top