Daphnia Culture Advice

[sparkyweasel]

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.

 

[MirandaB]

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.

 

[jameson_uk]

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.

 

[MirandaB]

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

 

[MirandaB]

At least I never asked you to taste them

 

[Wookii]

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:

 

[jameson_uk]

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?

 

[dw1305]

Hi all,

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

 

[jameson_uk]

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.

 

[dw1305]

Hi all,

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.

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.

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

 

[jameson_uk]

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.

 

[dw1305]

Hi all,

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.

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.

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.

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

 

[jameson_uk]

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)

 

[dw1305]

Hi all,

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.

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.

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

 

[jameson_uk]

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 😀

 

[jameson_uk]

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

 

[Steve Buce]

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

 

[jameson_uk]

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?)

 

[dean]

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


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[dean]

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


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