Daphnia Culture Advice

jameson_uk

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I ordered some Daphnia kits and I am looking for some advice on how to get the best out of them.
The kits came with a 4 litre ice cream tubs and some pellets (which it says contains bacteria but I am not entirely sure what these actually are).
I am not sure how well these kits are doing and it appears the number of daphnia is actually dropping.

Container
Everything says bigger is better but I don't have too much space to keep them and a toddler on the loose means they need to be reasonably protected. I am guessing the ice cream tubs are OK but not ideal. Would I be much better off getting something like one of the cheap 24 litre acrylic tanks from P@H? Also in terms of setup I have read a few articles about adding a small amount of substrate and / or plants. Is there any need to do so as most articles seem to only have water,

Placement / Light
There seems to be a lot of conflicting info about placement. Some say in direct sunlight, other says ambient light and some have said that light isn't an issue and doesn't matter. Does where I place the container make that much difference? I am guessing that outside is currently not an option?

Aeration
There seems to be a split about whether any aeration is necessary. Some articles say it will kill the daphnia as they want still water and others say to add some to stop the water going stagnant. Is adding a small air stone beneficial or not?

Feeding
As I said, I have no idea what the pellets that came with the kit are but they look a bit like some of the catfish pellets I have but I haven't seen mention of these anywhere else. I know @dw1305 has linked to this previously which suggests just adding straw which seems like the simplest way to go but any input appreciated.

Any other advise appreciated.
 

dw1305

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Hi all,
I am guessing the ice cream tubs are OK
Absolutely fine.
Some say in direct sunlight
Definitely direct sunlight at this time of the year, and add some plant fertiliser.
whether any aeration is necessary.
No, I don't have any now, I just change a small amount of water.
some pellets
Daphnia feed by sieving out particles of a certain size from the water column, they don't know or care what they are, it is purely size based. In nature this is normally green water algae, but you can substitute that for gram flour, paprika, yeast, astaxanthin powder etc. Smaller Daphnia eat smaller items, down into bacteria sized particles.
suggests just adding straw which seems like the simplest way to go
It isn't anything like as <"productive as using yeast"> etc., but you don't tend to get the same issues with "boom and bust". You could try the dried grass (Hay) pellets they feed to Guinea Pigs etc.

I should also have said add a Ramshorn Snail and some Blackworms or Asellus etc (if you have them) to the cultures.

cheers Darrel
 
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jameson_uk

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No idea why https://www.ukaps.org/forum/threads/small-daphnia-culture.59053/ didn't seem to come up whilst I was searching but that has a lot of help :angelic:

Definitely direct sunlight at this time of the year, and add some plant fertiliser.
Out of interest, what does the fertiliser achieve?
Is there any merit adding a couple of bits of frogbit?

Daphnia feed by sieving out particles of a certain size from the water column, they don't know or care what they are, it is purely size based. In nature this is normally green water algae, but you can substitute that for gram flour, paprika, yeast, astaxanthin powder etc. Smaller Daphnia eat smaller items, down into bacteria sized particles. It isn't anything like as <"productive as using yeast"> etc., but you don't tend to get the same issues with "boom and bust". You could try the dried grass (Hay) pellets they feed to Guinea Pigs etc.
I am guessing dried grass (came across this which I am guessing will be OK) will take a while to kick in so something like spirinula powder would be advisable whilst this matures? (I am getting some spirinula anyway for my shrimp)

I should also have said add a Ramshorn Snail and some Blackworms or Asellus etc (if you have them) to the cultures.
I did read about adding shrimps and snails but I wasn't sure what they actually achieve. I have plenty of bladder snails in my hospital tank (that got a bit neglected and they have thrived), some blue ramshorns and some tiny little ramshorns so should have to add.
Are they to help clean up what the daphnia don't and if so might adding some of the lower grade shrimp be beneficial (although slightly reluctant to go for shrimp in a filterless tank)
Do blackworms require substrate and would they be OK in a 4l tub?
 

dw1305

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Hi all,
No idea why https://www.ukaps.org/forum/threads/small-daphnia-culture.59053/ didn't seem to come up whilst I was searching but that has a lot of help
I'd forgotten all about that one as well. I've posted pretty much the same content, <"on culturing Daphnia">, on <"several forums"> over the last ~15 years, so it should be hiding all over the WWW.
Out of interest, what does the fertiliser achieve?
Hopefully gives you a bloom of green water, as the Daphnia population grows it won't be maintainable (they will eat it more quickly than it can reproduce) but it gets things going by providing an all day buffet. If you don't have a source of green water <"bird baths are quite useful">.
Is there any merit adding a couple of bits of frogbit?
Usually you don't have a higher plant, but it won't do any harm, it must compete for nutrients and light with the algae, but the <"Blackworm Buckets"> always have Daphnia in them and they are full of higher plants. I don't always use Frogbit in the Daphnia cultures, but have the snail etc to eat the filamentous green algae from the container walls. Usually any "spare" container ends up with Frogbit, because I always have more Frogbit than space and I don't like composting it.
I did read about adding shrimps and snails but I wasn't sure what they actually achieve.
They are just clean up crew. Bladder snails will be fine. Blackworms don't actually require a substrate, although they are definitely happier with one.
I am guessing dried grass (came across this which I am guessing will be OK) will take a while to kick in so something like spirinula powder would be advisable whilst this matures? (I am getting some spirulina anyway for my shrimp)
The hay should be fine. I always PYO mine. I've not tried Spirulina powder, but it should work. I'm too mean to buy anything specially and paprika and gram flour were to hand.

cheers Darrel
 
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Wookii

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I'd like to have a go at this, as hatching brine shrimp has proved quite labour intensive, and my fish haven't been overly impressed with grindal worms.

So I'd need a container, a window sill that gets direct sunlight, some guinea pig straw pellets, and a bag of daphnia from the LFS to seed it?

Some initial questions:

1. Assuming I use tank water, how long should it be left to 'green' before adding the daphnia?
2. How frequently do you need to change the pellets?
3. How much water would you change and how frequently?
4 How many feeds a week would you expect to gain from a 2 litre tub culture (feeding, say 10 small tetra at a time)?
5. Larger adult daphia have proven too large for my fish ti eat when I've fed them live and frozen previously - presumably using a culture I could harvest younger/smaller daphnia (though obviously not selectively)?
 

dw1305

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Hi all,
........and my fish haven't been overly impressed with grindal worms.
That is interesting, which fish? I've never owned any fish that doesn't really like them.
Assuming I use tank water, how long should it be left to 'green' before adding the daphnia?
Ten days should be plenty.
How frequently do you need to change the pellets?
I don't tend to remove the hay after I've added it, I just wait until productivity has dropped off and then I add some more.
How much water would you change and how frequently?
I change about 50%, but pretty infrequently.
How many feeds a week would you expect to gain from a 2 litre tub culture (feeding, say 10 small tetra at a time)?
You could feed some every day. Feeding yeast, algae and gram flour is a more productive, but you need to keep a much closer eye on the cultures and you need to harvest some Daphnia every day or "bust" is inevitable. There is a useful cost benefit breakdown in <"Doug Sweet's - Daphnia culturing made simple">.
Larger adult daphnia have proven too large for my fish ti eat when I've fed them live and frozen previously - presumably using a culture I could harvest younger/smaller daphnia (though obviously not selectively)?
Pour them through a net and then return any large ones that are caught to the culture tank, and feed the smaller ones that have gone through.

cheers Darrel
 
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Wookii

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Thanks as always Darrel.

Hi all, That is interesting, which fish? I've never owned any fish that don't really like them.

Ember tetra, chilli rasbora and pygmy cory's. Don't get me wrong, they do eat them, just not very enthusiastically, and they seem ignore half of them. I think it might be a size thing - some of the grindal worms are larger - though they also end up ignoring some of the smaller ones too. Some of the fish even eat some of the worms and then spit them back out again. It's a relative thing, and I'm comparing it to the brine shrimp or dried food - with the former they all literally go into a feeding frenzy.

I change about 50%, but pretty infrequently.

Would that be monthly , quarterly, annually - roughly?
 

dw1305

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Hi all,
Would that be monthly , quarterly, annually - roughly?
Fortnightly to monthly.
Ember tetra, chilli rasbora and pygmy cory's..... and I'm comparing it to the brine shrimp or dried food - with the former they all literally go into a feeding frenzy
No, that makes sense, my Pygmy Cories eat Grindal worms, but the thing that really gets them going are Micro worms.

cheers Darrel
 

Wookii

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Hi all, Fortnightly to monthly. No, that makes sense, my Pygmy Cories eat Grindal worms, but the thing that really gets them going are Micro worms.

cheers Darrel

Yep, I debated between grindal and micro worms at the time, and thought micro worms might be too small :banghead:
 

dw1305

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Hi all,
and thought micro worms might be too small
They are really small, but the <"Copella"> eat them as well.

I'd definitely get a culture. Micro worms are incredibly low maintenance, I had a look earlier and a <"starter culture was £3.50">.

Mine might actually be "Banana Worms", but you only need one out of Micro, Walter and Banana Worms, they are all much of a muchness.

cheers Darrel
 

sparkyweasel

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5. Larger adult daphia have proven too large for my fish ti eat when I've fed them live and frozen previously - presumably using a culture I could harvest younger/smaller daphnia (though obviously not selectively)?
You could try Moina, they are very similar to Daphnia, but smaller. Amazon and E-Bay usually have starter cultures.
 

Wookii

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You could try Moina, they are very similar to Daphnia, but smaller. Amazon and E-Bay usually have starter cultures.

I can't find any on Amazon, but eBay has them for around £10 (give or take) for part filed capsule of eggs - that doesn't seem many, but reading about them they appear to be pretty prolific (increasing in population by a factor of 6-12 every 48 hours :oops:)?

Do we think these containers would be suitable if I drill holes in the lids (need to avoid spillage if the kids knock them)? - Amazon

I can't seem to find any straw pellets listed anywhere - would I be better getting a small of natural straw or hay and tying up a small bundle?

Edit: Just seen these: Amazon - any good?
 
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from experience running a lot of tests using daphnia, they can crash for many unknown reasons, so having lots of smaller cultures on the go is preferable to fewer larger containers

Having a stash of old plastic bottles out the way going green is handy, when things kick off and you find the population is increasing at a rapid rate. Used cultured feed and peri pumps to deliver, but having a steady supply of the real deal is always better, if a little more time consuming
 

dw1305

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Hi all,
small of natural straw or hay and tying up a small bundle
Just seen these: Amazon - any good?
Yes and yes.
Do we think these containers would be suitable if I drill holes in the lids
Also yes.
from experience running a lot of tests using daphnia, they can crash for many unknown reasons, so having lots of smaller cultures on the go is preferable to fewer larger containers. Having a stash of old plastic bottles out the way going green is handy
Good advice.

cheers Darrel
 

jameson_uk

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Used cultured feed and peri pumps to deliver, but having a steady supply of the real deal is always better, if a little more time consuming
Sorry but I lost you with this bit o_O

If you don't have a source of green water <"bird baths are quite useful">.
Might be out to drain the bird bath later (is bird poo an issue though?)
just clean up crew. Bladder snails will be fine. Black
worms don't actually require a substrate, although they are definitely happier with one.
I have popped in a few pond snails and moved the tubs up into the study on the windowsill and there seems to be lot more movement than when they were on the side in the kitchen. I will probably need to monitor the temperature being next to the radiator though (and I really do need to clean the windows:eek:)

How full of daphnia are these 4l tubs likely to get before causing issues?


PXL_20201015_115025967.MP.jpg
 
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spin them round, have as much of the container in the sun as possible, you want green water to feed the daphnia

personally id have staggered their starts, this also helps if there’s a crash, there’s an understudy not far away to step up.

the lack of food, is one of the limiting factors,
and no the poo is fine, commercial fish/shrimp farms use animal muck to create a bloom and provide a basis to a food chain
 

dw1305

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Hi all,
Sorry but I lost you with this bit
So a peristaltic (dosing) pump picks up the green water solution from a culture vessel and dispenses it (in a continual trickle of algae) to the Daphnia.
Might be out to drain the bird bath later (is bird poo an issue though?)
Just take some of the water, it is only when the bath is dry you get the red resting cysts of <"Haematococcus pluvialis">, when the bath is wet they will be in suspension in the water column.

Any pond, or semi-permanent puddle, will have green algae in it. They can build up to huge abundance <"in the right conditions">.
How full of daphnia are these 4l tubs likely to get before causing issues?
Normally I'd say watch the colour of the Daphnia, when you look through the water, and it (the Daphnia really) looks noticeably pink, then its time to sub-culture. I know that you are red green colour blind (I'm not a stalker, @jameson_uk mentions it in <"Duckweed Index says"..>), so you may need someone else to do it.

cheers Darrel
 
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jameson_uk

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Just take some of the water, it is only when the bath is dry you get the red resting cysts of /microscopesandmonsters.wordpress.com/2013/10/06/an-encounter-with-a-green-alga-that-is-red/']Haematococcus[/URL] pluvialis"[/I]>, when the bath is wet they will be in suspension in the water column.

Any pond, or semi-permanent puddle, will have green algae in it. They can build up to huge abundance /www.ukaps.org/forum/threads/a-question-dissolved-oxygen-and-a-pond.58304/#post-569339']in the right conditions[/URL]">.
Found a pot outside that seems to have been flooded for a while. Took a bit of water from this and from the bird bath and now both tubs look a lot greener (well I think it is green! Who knew fish keeping was difficult if you're colourblind )
 

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