# Daphnia Culture Advice



## jameson_uk (14 Oct 2020)

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.


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## dw1305 (14 Oct 2020)

Hi all, 





jameson_uk said:


> I am guessing the ice cream tubs are OK


Absolutely fine. 





jameson_uk said:


> Some say in direct sunlight


Definitely direct sunlight at this time of the year, and add some plant fertiliser. 





jameson_uk said:


> whether any aeration is necessary.


No, I don't have any now, I just change a small amount of water. 





jameson_uk said:


> 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. 





jameson_uk said:


> 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 (14 Oct 2020)

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 



dw1305 said:


> 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?


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## dw1305 (14 Oct 2020)

Hi all,





jameson_uk said:


> 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. 





jameson_uk said:


> 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">.





jameson_uk said:


> 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. 





jameson_uk said:


> 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.  





jameson_uk said:


> 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 (14 Oct 2020)

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)?


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## dw1305 (14 Oct 2020)

Hi all, 





Wookii said:


> ........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. 





Wookii said:


> Assuming I use tank water, how long should it be left to 'green' before adding the daphnia?


Ten days should be plenty. 





Wookii said:


> 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. 





Wookii said:


> How much water would you change and how frequently?


I change about 50%, but pretty infrequently. 





Wookii said:


> 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">.





Wookii said:


> 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 (14 Oct 2020)

Thanks as always Darrel.



dw1305 said:


> 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.



dw1305 said:


> I change about 50%, but pretty infrequently.



Would that be monthly , quarterly, annually - roughly?


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## dw1305 (14 Oct 2020)

Hi all, 





Wookii said:


> Would that be monthly , quarterly, annually - roughly?


Fortnightly to monthly. 





Wookii said:


> 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


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## Wookii (14 Oct 2020)

dw1305 said:


> 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


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## dw1305 (14 Oct 2020)

Hi all, 





Wookii said:


> 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


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## sparkyweasel (14 Oct 2020)

Wookii said:


> 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.


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## Wookii (14 Oct 2020)

sparkyweasel said:


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



Thanks. Is the care of them identical?


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## dw1305 (15 Oct 2020)

Hi all, 





sparkyweasel said:


> You could try _Moina_,


A lot of fish prefer _Moina, _I've never managed to keep them for long, possibly because they've always become contaminated with larger _Daphnia. _


Wookii said:


> Is the care of them identical?


Yes.

cheers Darrel


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## Wookii (15 Oct 2020)

sparkyweasel said:


> 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 )?

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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## not called Bob (15 Oct 2020)

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


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## dw1305 (15 Oct 2020)

Hi all, 





Wookii said:


> small of natural straw or hay and tying up a small bundle





Wookii said:


> Just seen these: Amazon - any good?


Yes and yes. 





Wookii said:


> Do we think these containers would be suitable if I drill holes in the lids


Also yes. 





not called Bob said:


> 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


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## jameson_uk (15 Oct 2020)

not called Bob said:


> 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 



dw1305 said:


> 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?)


dw1305 said:


> 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)

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


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## not called Bob (15 Oct 2020)

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


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## dw1305 (15 Oct 2020)

Hi all, 





jameson_uk said:


> 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._


jameson_uk said:


> 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">.





jameson_uk said:


> 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 (15 Oct 2020)

dw1305 said:


> 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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## sparkyweasel (15 Oct 2020)

Wookii said:


> Thanks. Is the care of them identical?


Yes. They should do well in your indoor containers, I keep mine outdoors and, like Darrel, I get other species arriving and outcompeting them after a while.


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## MirandaB (15 Oct 2020)

What do the pellets smell of that came with the kit @jameson_uk ? 
They might be organic chicken manure pellets...I use those for my outdoor cultures along with green water.
Oddly enough since using that I've not had  boom and bust event in any of them.


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## jameson_uk (15 Oct 2020)

MirandaB said:


> What do the pellets smell of that came with the kit @jameson_uk ?
> They might be organic chicken manure pellets...I use those for my outdoor cultures along with green water.
> Oddly enough since using that I've not had boom and bust event in any of them.


Just got strange looks off the wife for sniffing them 

I would describe the smell as a bit like when you go into a barn at a children's farm. A bit grassy mixed with wee.


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## MirandaB (15 Oct 2020)

If the kit came from the seller I think it might be,I'm almost certain they are those pellets.


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## MirandaB (15 Oct 2020)

At least I never asked you to taste them


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## Wookii (15 Oct 2020)

jameson_uk said:


> Just got strange looks off the wife for sniffing them



😂😂😂 Brilliant - I’ve got a mental image of you in the corner of your room sniffing the pellets:


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## jameson_uk (18 Oct 2020)

So after adding a bit of the hay and some of the water from the garden there is a pretty thick build up on the surface. Should I skim this off or just leave it?


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## dw1305 (18 Oct 2020)

Hi all, 





jameson_uk said:


> Should I skim this off or just leave it?


I would probably skim it off with some kitchen towel, just in terms of gas exchange, but my guess is that it won't make much difference.

I use less hay than that (probably about 1/2 as much) but I'm not after very quick population growth. When I'm trying to "breed" mosquitoes in the summer outside I use more grass than that, and those cultures will still support _Daphnia._

cheers Darrel


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## jameson_uk (22 Oct 2020)

So there has been a definite lightening of the water which I guess is the contents getting eaten.
The culture on the left seems to be doing pretty well and there are lots of daphnia and they are getting quite large






But the one on the right has far fewer daphnia and they are tiny.   It is also starting to smell (not sure how I would describe it but is isn't pleasant, sweaty socks?) .
Other than changing a bit of water in the right hand container is there anything I ought to do?   Might I have introduced some sort of predator from the water sourced from the garden (they both had water from the same source so just seems a bit odd that only one smells).   Photos are about the same zoom level and both cultures have basically been given identical care.


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## dw1305 (22 Oct 2020)

Hi all,


jameson_uk said:


> far fewer daphnia and they are tiny


They look like a <"Copepod _Cyclops_">_. _Fish absolutely love them, but they are more difficult to culture in large amounts.


jameson_uk said:


> The culture on the left seems to be doing pretty well and there are lots of daphnia and they are getting quite large


They are doing really well. I'd sub-culture them now.


jameson_uk said:


> Other than changing a bit of water in the right hand container is there anything I ought to do?


Add some tap water? You often get a swap from Cladocerans to Copepods as carbonate hardness falls.

cheers Darrel


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## jameson_uk (22 Oct 2020)

dw1305 said:


> They look like a <"Copepod _Cyclops_">_. _Fish absolutely love them, but they are more difficult to culture in large amounts.


The larger ones are Daphnia though?   Now looking at pictures I can't tell .   When they first arrived and were in clear water there was definite jerky movement not I am not seeing much of that now and they seem to be congregating in the corners.
There are most definitively some cyclops in both containers as these are the ones that look (in my head anyway) like space rockets.  I wonder whether these came with the daphnia or from outside?   






> They are doing really well. I'd sub-culture them now.


Any tips to get them out?    Just submerge a beaker to suck them in and pour into a new container?
Also order of magnitude are we talking about for how many daphnia should I be expecting in one of these four litre containers?



> Add some tap water? You often get a swap from Cladocerans to Copepods as carbonate hardness falls.


Interesting.   Whilst my GH is relatively high the KH is only 5.   The containers were filled about half full of aquarium water so I guess the KH probably has dropped quite low.
Will have to figure out the opposite of above where I want to take some water out and not the occupants....  I guess I just put everything through the net and put anything that does get caught into the tanks.


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## dw1305 (22 Oct 2020)

Hi all,


jameson_uk said:


> or from outside?


Probably from outside, I find them in the water butts, blackworm buckets etc. There are always a few, but rarely very many.


jameson_uk said:


> Any tips to get them out? Just submerge a beaker to suck them in and pour into a new container?


Beaker will do, or use a net. The numbers will build up again fairly rapidly.


jameson_uk said:


> are we talking about for how many daphnia should I be expecting in one of these four litre containers?


I would let them get any denser than they are at the moment in the left container. Population growth is pretty exponential and, in my experience, boom is inevitably followed by bust.


jameson_uk said:


> I guess I just put everything through the net and put anything that does get caught into the tanks.


Tip it through a fine net and then just repatriate the inhabitants. I'd be tempted to just replace any evaporation with tap water at the moment. You have a spare culture should anything horrible happen, as I'm not sure about _Daphnia_ and dechlorinators etc.

If you are going for a larger water change I'd let the tap water stand for a couple of days.

If you already have potassium bicarbonate (KHCO3)? you can add a pinch of that.

cheers Darrel


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## jameson_uk (22 Oct 2020)

dw1305 said:


> I would let them get any denser than they are at the moment in the left container. Population growth is pretty exponential and, in my experience, boom is inevitably followed by bust.


Even though this is just one corner of the container? (seems most of the occupants had crammed themselves into about 1% of the container).   Just trying to get a feel of when to do it (I haven't actually harvested any for the fish yet)
I will try and get some water in a container with some hay tonight then look at transferring some across over the weekend..


> I'd be tempted to just replace any evaporation with tap water at the moment. You have a spare culture should anything horrible happen, as I'm not sure about _Daphnia_ and dechlorinators etc.
> 
> If you are going for a larger water change I'd let the tap water stand for a couple of days.
> 
> If you already have potassium bicarbonate (KHCO3)? you can add a pinch of that.


I don't have any KHCO3 but I am might as well just use water from my main tank? (the KH never seems to drop much in my main tank)


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## dw1305 (22 Oct 2020)

Hi all,


jameson_uk said:


> I don't have any KHCO3 but I am might as well just use water from my main tank?


Yes that should be fine, it just needs some dKH.


jameson_uk said:


> I haven't actually harvested any for the fish yet


Harvest some every day. If you don't have many, just harvest a few, if you have a lot, harvest more. If number start declining? add some more hay or pellets etc. and then don't harvest again any until you get back to a reasonable population.


jameson_uk said:


> Even though this is just one corner of the container?


OK,  you are good for a while then. I thought looking at the container (from above) that all the pinky dots were _Daphnia._

cheers Darrel


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## jameson_uk (22 Oct 2020)

dw1305 said:


> OK,  you are good for a while then. I thought looking at the container (from above) that all the pinky dots were _Daphnia._


The dots over where the hay is tied together are a little paprika which I think was glistening in the sunlight


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## jameson_uk (25 Oct 2020)

dw1305 said:


> Hi all, I would probably skim it off with some kitchen towel, just in terms of gas exchange, but my guess is that it won't make much difference.
> 
> I use less hay than that (probably about 1/2 as much) but I'm not after very quick population growth. When I'm trying to "breed" mosquitoes in the summer outside I use more grass than that, and those cultures will still support _Daphnia._
> 
> cheers Darrel


This film has got worse and worse despite me skimming it off with kitchen towel.   It isn't like any biofilm I have seen before (and the like I sometimes get on the betta tank where the surface is still) and it was basically gelatinous and this is very much the stuff that stinks.   I have removed as much as I can manually and hopefully I haven't lost too many occupants.   I believe daphnia are attracted to light so I currently have the jug holding the gloop under a desk light to see what comes to the surface, if there are lots I will try and repatriate these.

I can't clear it completely though and I do wonder how long it will be before it comes back.   Seems odd as both containers have had the same same treatment, same water, same contents...  and no signs of this at all in the other container


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## Steve Buce (25 Oct 2020)

My set up in the outhouse fishroom, tank water, spirulina and some ferts






Feed every couple of days with spirulina powder, w/c bout once a week .
Seems to work ok for me


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## jameson_uk (31 Oct 2020)

So as predicted the slime in the right hand culture has come back. It is a bit like thin snot.

Just wondering if the oxydator I have in my shrimp tank might help? (Although I suspect being around 19°C the oxygen levels are going to be relatively high even with this gunk?)


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## dean (1 Nov 2020)

I’ve found a really easy way to raise daphnia 
I use large tubs 400litres + but it could easily be scaled down 

Fill container with my hma filter add some mature aquarium water from water change 
I add snails any type 
Then I simply throw in vegetables but I’ve found banana skins are really good 

Please correct me if my science is wrong but I think the banana skins snd snails help produce infusoria which feeds the daphnia 

Also the tubs are in full daylight and in the summer they didn’t go green just cloudy and there’s no algae on the surfaces as there’s such a large colony of snails 

Aeration - I use solar power floating pumps only £7 but I covered the inlet with a piece of foam to stop the daphnia being minced by the impeller, if you wanted to aerate a smaller container / aquarium I would use a weighted airline no air stone just open ended and reduce the flow to one bubble a second as the daphnia don’t need it, place it just below the surface so it doesn’t create a flow that the daphnia have to swim against 

I believe a deeper container works better than a shallow one 

On the odd occasion I’ve not had banana skin or lettuce leaves I’ve fed some fish food to the snails 


Sent from my iPhone using Tapatalk


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## dean (1 Nov 2020)

Here’s some pics of the set up and the daphnia 


Sent from my iPhone using Tapatalk


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## Wookii (1 Nov 2020)

So I have finally received the Moina cysts and hay blocks:





Given the size of the blocks, how much should I be adding to a 4 litre container like this?:





The water is rainwater with a little ferts added, though it’s not greening up very much given the lack of sunlight currently.

Once I add the straw block, how long should I wait before adding the cysts?


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## dw1305 (1 Nov 2020)

Hi all, 


Wookii said:


> how much should I be adding to a 4 litre container like this?:


About 10%? You can always add more as you go along.

cheers Darrel


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## jameson_uk (7 Nov 2020)

I now have strike one with the wife telling me the study smelt of stagnant water. Luckily it is me who is working in there so I probably have some time before strike two....

This slimy gloop keeps coming back (and is now there to some extent in both containers).

Presumably smelling isn't a good sign? 
Seems to be a lot less Daphnia than there was so I am Tempted to chuck these and start again.


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## not called Bob (8 Nov 2020)

sounds like its gone stagnant, never used any straw etc in cultures before, but I assume its rotted and fouled the water


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## dw1305 (9 Nov 2020)

Hi all, 


not called Bob said:


> never used any straw etc in cultures before, but I assume its rotted and fouled the water


Too much hay is my guess as well. Just net the remaining _Daphnia, _and start again.

cheers Darrel


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## jameson_uk (9 Nov 2020)

dw1305 said:


> Too much hay is my guess as well. Just net the remaining _Daphnia, _and start again.


I have done a little experimenting over the weekend and changed some water and also added a tiny air pump with really low flow.   This does seem to have cleared what I can see of the gloop and reduced the smell but it is still there.
I am not sure how much has actually survived; there are certainly a few small daphnia in there but all the bigger ones seem to have vanished and I can't see any Copepods (at one point I could see quite a lot).  Obviously the bladder snails seem fine and have actually grown a lot bigger than they do in my tanks.

What I am not sure if how much I can net out without taking some of the gunk.    I have read differing opinions on whether they are attracted to light or not.   I might try sticking a light over the containers and seeing if anything does come to the surface.  The other thing I read was about eggs being dormant in the gunk so not entirely sure whether I am better off throwing everything, cleaning up and starting again or keeping some of what has built up.  Given the sachets of live daphnia cost 
£1.50 at LFS I am tempted to reset everything and this time leave the hay for a while before adding the daphnia?

Other than ease of removing it is there any need to tie the hay up?  (Every pic I have seen has it tied up in a nice bundle so I did without really thinking about it)   Adding loose bits I guess would form more of a layer on the bottom than tying it up and this probably isn't as good for them as they seem to want to be higher up in the water?


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## jameson_uk (9 Nov 2020)

After peering in for a while I think I may have another vote to restart.    An unnatural movement caught my eye whilst I was seeing what if anything has actually survived and then obviously promptly vanished before I could get a picture.
There was something clear / greeny / brown about 10-15mm long and probably only 1-2mm wide on the side of the container.   It seemed to attach itself to the container and then straighten out so it was vertical and then launch.   It formed a sort of Omega shape then sprang back to being straight (and then vanished).

This is obviously in some murky water, happened in a few seconds and has been observed by a colour blind person so these details may or may not be accurate...  (I am guessing green / brown as it was kind of camouflaged)
The movement suggests a leech?   (although I didn't see it change width only curl up and propel itself).

Either way I am presuming it is probably not desirable in with daphnia?


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## jameson_uk (10 Nov 2020)

I have removed the hay (which stank) and will get around to sorting things out over the weekend.   I did however see the _bug_ again and I guess this isn't a leech but I cannot match it to anything I have seen on line.

It was hanging about mid water (definitely looking predatory) and I am guessing it is some sort of larvae?  Gives me the creeps 👾


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## dw1305 (10 Nov 2020)

Hi all,


jameson_uk said:


> . I did however see the _bug_ again and I guess this isn't a leech but I cannot match it to anything I have seen on line.
> 
> It was hanging about mid water (definitely looking predatory) and I am guessing it is some sort of larvae?


It is a <"Glassworm" (_Chaoborus_)">, a predatory midge larvae (they actually eat _Daphnia_). They need quite high quality water, so in some ways it is a positive find.

Fish *love them, *but they are difficult to culture, so are usually wild caught as by catch with _Daphnia._



cheers Darrel


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## jameson_uk (10 Nov 2020)

dw1305 said:


> It is a <"Glassworm" (_Chaoborus_)">, a predatory midge larvae (they actually eat _Daphnia_). They need quite high quality water, so in some ways it is a positive find.
> 
> Fish *love them, *but they are difficult to culture, so are usually wild caught as by catch with _Daphnia._


Just spotted there are two in there (I guess there are most likely more) and they are real buggers to catch (well using the beaker I had to hand anyway)
Are these likely to have come from the shop bought live daphnia or from the water from bird bath / garden tub?  (Just thinking about when I do clean it out a little and add some more daphnia)



> David Livingstone (1865) claimed that they "tasted not unlike caviare"


Not sure I fancy trying to eat them.


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## dw1305 (10 Nov 2020)

Hi all, 


jameson_uk said:


> have come from the shop bought live daphnia


Would be my guess.

cheers Darrel


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## not called Bob (10 Nov 2020)

try a long plastic pipette for collecting them, used to use that to also separate daphnia out


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## jameson_uk (10 Nov 2020)

dw1305 said:


> Would be my guess.


Not ideal to include a predator with them then!!!   Is this common as just thinking about starting up again and if I source daphnia from LFS and it includes glassworm then they are quite hard to spot in green water.   Am I better off getting a better source of daphnia or just picking them out if / as I find them?

It was only when I saw the video and then read another article that I realised that they are _White Mosquito Larvae_.  I feed these frozen and fish love them.


not called Bob said:


> try a long plastic pipette for collecting them, used to use that to also separate daphnia out


I have a turkey baster I used to use to remove uneaten food from the shrimp tank so will give that a go.


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## BigD (10 Nov 2020)

Glassworm are easy to spot in a bag of daphnia.  Just ask the LFS for a back that does not contain them.  There are rarely more than a couple in a bag, so removing the two that you have should be sufficient.


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## Wookii (13 Nov 2020)

So I’m calling my first attempt at hatching the Moina a bust, I can see anything moving in the water column after over a week. This time I’ll leave the hay out until later and start the Moina off with the yeast that came with the starter pack:





The snails have thrived though, and laid eggs everywhere! Can anyone hazard an ID?:


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## dw1305 (13 Nov 2020)

Hi all, 


Wookii said:


> Can anyone hazard an ID?:


Tadpole Snail (_Physella acuta_).

cheers Darrel


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## jameson_uk (27 Dec 2020)

So I have been busy and largely ignored these cultures and never got around to resetting them but a few weeks ago I took a couple of liters out and replaced it with water from one the tanks after a water change as the water wasn't looking great.
One of the containers has gone crazy and needs to be harvested, only problem is the net I bought of Amazon it too big to really fit in the containers so I may have some fun trying to do this later...

One container however is still really struggling with the gunky layer on the surface.  It seems even if I use kitchen towel on it daily it is just coming back and is really incredibly thick and gloopy.  When removed it seems to kind of solidify a little and leave whiteish clumps which is odd.

The water I took out of both containers got dumped in a bucket, my main plan here was to remove a lot of the gunk that had built up on the bottom and once the contents of the bucket had settled repatriate any daphnia.    Needless to say I haven't had time and there are quite a few daphnia in there now but that is also suffering from a build up on the surface (although nowhere near as bad as the second container).

Why is this build up so bad in just one container?     Is it just biofilm that has built up?


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## jameson_uk (29 Dec 2020)

So took a photo of the film today and you can see it coming together into white strands when I run my finger through it.    Looks kind of like shredded plastic but doesn't really hold together if you take it out the water.
What is this?


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## dw1305 (29 Dec 2020)

Hi all,


jameson_uk said:


> Looks kind of like shredded plastic but doesn't really hold together if you take it out the water.
> What is this?


Looks like it might be a layer of wax.


jameson_uk said:


> needs to be harvested, only problem is the net I bought of Amazon it too big to really fit in the containers so I may have some fun trying to do this later...


Pour the water through a net, into another container, so you don't lose the smaller _Daphnia_ etc.

cheers Darrel


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## jameson_uk (29 Dec 2020)

dw1305 said:


> Looks like it might be a layer of wax.


Where might that have come from?



> Pour the water through a net, into another container, so you don't lose the smaller _Daphnia_ etc.


I have standard fish nets and a muslin type one. The fish net seems to let everything (including this build up) through and the muslin only lets the water though....

Are you suggesting to get the Daphnia and water through and catch anything else or to let the gunk go through the net and leave the Daphnia behind?


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## dw1305 (29 Dec 2020)

Hi all,


jameson_uk said:


> Where might that have come from?


From the plant material, mixed up with bacteria, fungus etc. You get it a lot on <"ponds etc">. I would just keep skimming it off if it bothers you, but I don't think it will bother the _Daphnia._


jameson_uk said:


> or to let the gunk go through the net and leave the Daphnia behind?


Net out the bigger _Daphnia_? and feed them? or alternatively collect the smaller ones that have gone through and tip them in the tank

If you use the muslin net could you let the _Daphnia_ swim out of the net into the fish tank?

cheers Darrel


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