Live food cultures

[BigBen]

Hi folks.

I've just ordered microworm started culture. What other tiny cultures can I use? Once the new tank arrives, I'll have a brine shrimp hatchery on the go, but until then, is there anything else that's any good?

Need to eat a tub of ice cream in the mean time.

Cheers, Ben.

[plankton]

@Vale! has a bath in the garden for live food, if you can find his thread on it.....

[saiwong]

I was thinking of starting a Daphnia culture (starting with ordering a couple of bags of live Daphnia).

Anyone who has experience, how easy or hard is it to raise Daphnia ?

How large a tank should I use or can I just use a large jar ?

Any need for regular water changes or do they generate minimum waste ?

[BigBen]

@Vale! is the man. He has a bath tub of the stuff!

[Vale!]

There's not a lot of them in the bathtub at the moment! It's my fault: I failed to prevent it overflowing during recent downpours and the vast majority of the remaining Daphnia made rather miscalculated bids for freedom! Anyway ...

Yes, @saiwong most years I maintain cultures, either of Daphnia or Moina (or both) over the Winter. This year my Daphnia attempt failed (twice!) due to my being unable to eliminate the Cyclops which seemed insistent on accompanying the Daphnia on their journey from the bath! So I turned it into a third Moina culture instead. Initially that failed as well, this time due to 'detritus' worms **; I got rid of those with a proprietary levamisole preparation, started again and now all is well.

So I don't have indoor Daphnia cultures this year and my remarks and pics relate to Moina. Exactly the same principle - just that Moina are less crunchy and more nutritious than Daphnia!

Container & General Conditions You can use a bucket (or two, since it's advisable to have more than one culture on the go!) so long as it's in a light and warm place. They need light to breed, optimally around 10-12 hours daily ; and temperature shouldn't be much lower than around 22C (I run my cultures even warmer than that). Add a heater if ambient is typically lower. An airline (big bubbles rather than fine) helps with oxygenation and with keeping food particles in suspension. If the airline can run through a cycled sponge filter, then so much the better.

Rather than buckets I use redundant tanks (actually two are home-made) of around 10-15 litre capacity. I find it much easier to maintain a culture when I can see what's going on in it! I'm lucky to have the space to be able to do that, I guess. If you happen to have odd corners where a small tank might fit, then a small tank would be far more preferable than a bucket. Here's where my three current Moina cultures are lurking:








Water Chemistry & Maintenance

I haven't tried keeping Daphnia in full tapwater so I don't know how they'd fare in Milton Keynes Municipal Masonry (aquaeous). I use a ratio of three litres of tapwater to 10 litres of reverse osmosis water which gives a pH of around 7.1 ; I maintain this in-culture with a little tub of coral sand (30g) and a hunk of cuttlebone. pH is checked regularly in case it dips below neutral for any reason and rectified with potassium carbonate if necessary (it rarely is). I also add Seachem Prime (each culture tank has a cycled filter) and a couple of drops of a trace element solution (I use Fresh Trace).

Water-changes are a couple or three litres per week. I just hoik out a couple of jugfuls, pour them through a suitable sieve (I use brine shrimp sieves of varying reticule size), return to the culture any creatures caught and then add fresh water.

The coating of algae that builds up on the tank glass (if not dealt with by creatures that may be co-cultured) can be scraped off from time to time: a modicum is good but too much may be a hindrance. I tend to clean only the front panel. I clean the airway of the sponge filter only when it becomes overwhelmed with algae.

The floor of the tank collects debris, much of which is composed of ex-Daphnia. It's best to keep on top of this if possible (though, again, there could be helpers in-tank!). I use a turkey baster to withdraw some/most/all of it. But then there's then the problem of what to do with all the living creatures that have got sucked up as well! To separate them: empty each turkey basterful into a jug. Top up with fresh water and then park a downward-shining torch on top for five minutes. The vast majority of refugee Daphnia (or Moina) will swim to the surface and can be decanted back directly into their tank. Rinse and repeat to retrieve even more.


I think I'm going to stop there momentarily and let you ponder whether you want to proceed; and, if so, how (bucket or tank). More info to come on feeding, co-culturing etc. if that wold be of value to you. In the meantime you can see two of the cultures in action, as it were, from the last couple of minutes or so of a video I posted t'other day; access via https://www.aquariumforums.co.uk/viewto ... 53#p122953




** which reminds me: I can post more details (of identity and of morphology) separately, including video, about these worms should anyone want me to.

[saiwong]

Thank you Vale for your detailed response.

From the YouTube videos I watched they made out that it was easy to culture Daphnia, but it seems to be a more tricky process in reality.

I currently setting up an environment for the Daphnia. I am taking some advice to use water taken from my main tanks (during water changes)
since they have 'green water' to help feed the Daphnia.

I am also using a thermometer I had acquired through purchase of an aquarium but it is fixed to temperature of 25C (is this temp OK?)

I got mixed messages on using a sponge filter. Some say it is OK, whilst others say that Daphnia will get sucked in and it is better for
you to just use a hose to create large bubbles & a turkey baster to suck up waste. What do you think ?

[Vale!]

Ha ha! Yes - I know what you mean about it looking easier said than done. Many of those videos, though, are made where a British Winter isn't a limiting factor!

Tankwater should be fine so long as its parameters are OK with the Daphnia (mine, for example, definitely isn't). It's unlikely (though perhaps not impossible) to be a problem.

Yes - I've got one of those heaters in one of my cultures, too. It'll be fine.

I'm sticking to my guns about the sponge filter thing. Daphnia are much more sensitive to ammonia than are fish ; and given the temperature and likely pH that you'll be maintaining, any ammonia that does appear will be more toxic than if the water were cool and sightly acidic. In which connection, btw, I have it in my head that Daphnia may be more tolerant of slightly-acidic water than are Moina - might be worth checking. I'm puzzled by the "get sucked in" suggestion - what kind of filter and/or airflow was the author thinking of, I wonder? Anyway, if you're not going to use a filter, then (obviously) you'll rely on testing and remedial water-changes as necessary.

I agree with "large bubbles". And turkey basters rule!

[LookoutTrout]

I can see microscopic animals living happily on and in my sponge filter, when I magnify it with my phone camera I can see them popping and and out of the filter with no hint of being sucked in.