# Daphnia culture crash



## SwimmyD

Hi everyone, I started a daphnia culture about 2 months ago. I kept the tank in the kitchen with lots of natural light and only light bubbling from an air tube. I fed them the dry yeast for a couple of weeks and noticed the disgusting yeasty stinky layer forming on the bottom after a few weeks. I scraped it off and vacuumed it up, and always added more water to the tank. Then after a few weeks I came across some "fresh yeast" at a deli. It's a block of fresh "alive" yeast that smells like old cheese. I started using it and then the population of daphnia EXPLODED. They loved it. The scummy layer on the bottom disappeared, and the daphnia were happy. So were my fish! I vacuumed up the dead bodies regularly and did water changes. I checked the smell of the tank almost daily to make sure nothing was out of whack.

About 4 days ago I noticed that my yeast had some mould on it. I scraped it off and fed the okay parts to my daphnia. Well the next day most of my daphnia were on the bottom. The death dance. Within a day most were dead! Ahhhhh! The water still smelled clean, and I cleaned the tank yesterday. Other than some mild expected brown scum (from dead dapnia over time) the tank was pretty clean. Not offensive at all. 

Anyways, I was told at some point that you need to start a new culture of daphnia. I'm assuming its to avoid a crash like this. Does anyone have any advice on when and why? The culture was totally awesome before the crash! Or did I kill them all from the old yeast! 

Thanks!


----------



## Jackson

I have not started a new one since I picked mine up from Igor. It has to be at least 3 months now and they're doing great. 
One culture is full of daphnia, blue ram horns and dero worms. I don't feed yeast regularly. I just feed the worms and snails. I'll feed yeast maybe once every two weeks. The other just has dero worms and daphnia. Feeding is the same as the other one.
WC's once a month with regular top ups. 
I keep both under a 23watt light bulb around 12 hrs a day. 
I've even left the light off for a week and they were fine. 

I'll try to take some pics or a video showing the two. 

I think you might of changed the water too often. 
When I do a water change I use water from my other tanks. I don't use fresh clean water.


----------



## LTPGuy

I am with Jackson on this.

I got about 10-15 from Igor about a year ago.

I keep my main culture in a plastic shoebox. I keep a backup culture in a small bowl (plastic one from instant noodles). 

I bubble without airstone enough to just break the surface tension so no film gets to form on the surface.

I do partial water change once in a while, mainly when I add the green water. I haven't used green water for weeks, and I just top off with tank water. No WC in either shoebox or noodle bowl.

I feed with Instant Dry Yeast from No Frills, and greenwater. No greenwater lately.

I've kept a small batch in as little as 1oz of water for weeks - in stinking (foul smelling) water with no aeration.

I have yet to see any kind of crash since day one. These little critters are incredibly resilient.

However, they are super sensitive to metalic ions in the water. Overpopulation will do it also. Can you guess the density of your culture at the time of the crash? # of daphnia per square inch?

How much yeast do you feed your culture. How big is the container? Overfeeding could be issues too. I used about 1/4 tsp soaked 2 minutes in 1oz of warm water prior to adding them to the culture daily. Sometime I skip a day when the water doesn't clear. 

I wonder if there might be toxin in your yeast from the mold?!

Try to walk through the steps you had taken prior to the crash. With more information, may be we can figure out what happened. So that everyone can learn from it!

As I said, I've done a lot of things that should have killed these critter but I have yet to see any kind of crash.

On your next setup, try to keep a backup culture. It doesn't have to be fancy. Mine's in a instant noodle bowl!

One more note. Direct sunlight is not good. Filtered through heavy shear might be OK. The water gets hot, drives off oxygen, raised water temperature. Furthermore, the algae in your water will generate micro-bubbles which get caught in their carapace. This causes them to float to the surface. They can't swim or requires a lot of energy to swim. Of course they died eventually. I am speaking from first hand experience.


----------



## Fishfur

Does anyone use a sponge filter with daphnia ? I've read they are useful, if only to reduce water change needs, and they won't damage the daphnia. And fwiw, I have read it's best to maintain at least two separate cultures, because daphnia tend to have 'boom and bust' population cycles, and may crash at any time, but particularly in the heat of summer. Having a spare culture can save losing them all.

I might guess the problem could have been from mould toxins. Fresh yeast has a pretty short life span, nothing like the dry stuff. It should be kept refrigerated. Oddly enough, yeast tends to discourage almost all mould growth when it's fed in it's dormant dry state to such things as microworm cultures. It would concern me if I saw mould growing ON yeast.

Not surprising the daphnia like fresh yeast. Nice fat juicy cells ready to devour.

The fact that some part of the yeast block looked all right, sadly, does not mean it was ok. The filaments that moulds grow are not easy to see and penetrate quite a bit deeper into whatever the mould is growing on than the visible part of the mould would suggest. Think of a fairy ring of mushrooms - what we call a mushroom is only the part we see above ground, and it is only the fruiting body of the plant. The remainder of the mushroom colony will be many, many feet larger in diameter than the visible mushrooms indicate. Same deal with moulds on foods. Most are fungi of some kind. IIRC, the largest single plant organism currently known to man is a huge mushroom colony, though I can't recall where it's located.

One thing I learned when all my allergies were diagnosed was what to do if I found moulds on food. Fungi & moulds give me hives.. potentially an anaphylactic reaction. My doc told me that mould on cheese, for example, can penetrate an inch or more past the mould I can see. I should toss it, but if I want to cut it off, I must remove at least one inch of clean looking cheese past the mouldy part, on all sides, to be reasonably sure it's gone. On many foods, any mould growth would be cause to discard it.. certainly with something the size of a fresh yeast block.


----------



## SwimmyD

Thanks everybody for your suggestions,
I keep them on the kitchen counter which is far away from the window, but lots of natural light. They were staying at a constant temperature of low 70's. I had a very slow bubbler, just enough to keep the surface broken. No air stone. There were hundreds of thousands. It was a HUGE culture. Probably a hundred per square inch (counting all the babies). Massive. The population explosion happened when I switched to the fresh yeast. The yeast was kept in the fridge at all times in a sealed bag. I fed enough to make the water cloudy, and it normally cleared in 2 days. Then I would add more. It's a cube of stuff, I just crumbled away enough to feed them. I didn't go nuts on water changes. I just vacuumed the dead bodies from the bottom, then topping up water from an established tank. 

I think I screwed up on the mouldy yeast. It must have been toxins in the mould. Arggghhhh. I killed them. I should have had a back up. I managed to salvage about 20 and have them in the bottom 3 inches of water of the cleaned tank. I will not feed them the mouldy yeast. Sadly I do not have green water. That would be way cleaner. It was the dry yeast that I found so disgusting. I though I found the miracle solution with the fresh yeast! It never left a film. But the deli where I got it is not that close. I need to plan better in future!


----------



## SwimmyD

Oh ya, and it's a 5g tank.


----------



## Fishfur

Well, if you need some green water I can sell you a culture to start with.. I have some going now. Let me know..so long as you keep reculturing it will carry on for a long time. You can refrigerate portions to maintain them alive longer too, if you have a bit too much on hand once it gets going.

Probably should have split it at least in half,once it boomed so big.. but live and learn, right ? Ve all screw up from time to time, yah ?

I'm surprised you even found fresh yeast, it's become something of a rare beast these days.. especially with the new 'quick rising' type of dry yeast that's around now.


----------



## BillD

For what it's worth, I willthrow in my observations. I closed my outdoor daphnia culture yesterday. It is an 18' x 36' by about 18" to 24" deep. It was the "pond" created by the winter cover on my swimming pool. I have had this going every spring since 1995, from one original culture. It has been my observation that early on the numbers grow very quickly, while the water is still cold and there is lots of food. As the water warms and the population increases,and the food dwindles, the daphnia will start to form cysts, which show as a ring around the edge. These form the basis for the next years culture, which starts even before all the ice is melted. I usually keep some going in pails left out and in a garbage can in the basement. I once visited the pond I sourced them from in the summer, when the water was still relatively high, and found none. This led me to believe that this particular strain may have been temperature sensitive. However, I have since had some survive the summer in a pail with no attention or feeding.
I have occasionally fed yeast to the indoor culture but rairly. Occasionally I will throw some rotting vegetable matter into the can to create some infusoria. Green water is easily the best source of food if you can create it. The spring of 95, I had green water that was like paint (dog defecated all over the pool through the winter), totally opaque and the population grew from 50 or 60 daphnia into the millions. They literally consumed all the green water in about 7 weeks. I have never had green water like that since, and still have far more daphnia than my fish can consume, so I freeze a few pounds. The daphnia are delivered to the garbage can in the basement via a garden hose siphon. The garbage can overflow via some holes through a sieve to anothe pail and then to the floor drain. I usually place a fine net in the cascade to collect the daphnia, and whatever else travel through the hose, usually bloodworms and other similar insect larvae. At his time the fish have daphnia in front of them 24/7.
Daphnia don't have a particularly high nutrient content (about 90% water), but if they are gut loaded with green water, this surely increases. Regardless, the sheer volume of food, results in a growth spurt in young fish. The high bulk content creates no digestive problems, even with mbuna. It does require more maintenance in the form of more frequent/larger water changes.
None of this is really scientific, but my observations indicate that temp, and food supply, are probably the main factors that influence how well a culture will do. As well, if a culture dies out, any remaining cysts can hatch and restart the culture if left, or allowed to dry out and then rehydrated. I believe that the presence or lack of cysts tell you the state of the culture.


----------



## Scotmando

BillD said:


> For what it's worth, I willthrow in my observations. I closed my outdoor daphnia culture yesterday. It is an 18' x 36' by about 18" to 24" deep. It was the "pond" created by the winter cover on my swimming pool. I have had this going every spring since 1995, from one original culture. It has been my observation that early on the numbers grow very quickly, while the water is still cold and there is lots of food. As the water warms and the population increases,and the food dwindles, the daphnia will start to form cysts, which show as a ring around the edge. These form the basis for the next years culture, which starts even before all the ice is melted. I usually keep some going in pails left out and in a garbage can in the basement. I once visited the pond I sourced them from in the summer, when the water was still relatively high, and found none. This led me to believe that this particular strain may have been temperature sensitive. However, I have since had some survive the summer in a pail with no attention or feeding.
> I have occasionally fed yeast to the indoor culture but rairly. Occasionally I will throw some rotting vegetable matter into the can to create some infusoria. Green water is easily the best source of food if you can create it. The spring of 95, I had green water that was like paint (dog defecated all over the pool through the winter), totally opaque and the population grew from 50 or 60 daphnia into the millions. They literally consumed all the green water in about 7 weeks. I have never had green water like that since, and still have far more daphnia than my fish can consume, so I freeze a few pounds. The daphnia are delivered to the garbage can in the basement via a garden hose siphon. The garbage can overflow via some holes through a sieve to anothe pail and then to the floor drain. I usually place a fine net in the cascade to collect the daphnia, and whatever else travel through the hose, usually bloodworms and other similar insect larvae. At his time the fish have daphnia in front of them 24/7.
> Daphnia don't have a particularly high nutrient content (about 90% water), but if they are gut loaded with green water, this surely increases. Regardless, the sheer volume of food, results in a growth spurt in young fish. The high bulk content creates no digestive problems, even with mbuna. It does require more maintenance in the form of more frequent/larger water changes.
> None of this is really scientific, but my observations indicate that temp, and food supply, are probably the main factors that influence how well a culture will do. As well, if a culture dies out, any remaining cysts can hatch and restart the culture if left, or allowed to dry out and then rehydrated. I believe that the presence or lack of cysts tell you the state of the culture.


I like this idea of the pool cover daphnia culture. When do you put the daphnia in?

SwimmyD, I have daphnia if you need


----------



## SwimmyD

Thanks again everyone,
Bill - are the cysts the brown scum that form on the water line? Because when I cleaned the tank I wiped it all off and threw it out. It was kind of gelatinous. How do you dry this stuff out? And what colour are your daphnia? Mine were white. When I went to PeterD's place for my killies, he showed me his "wild" daphnia caught from his pool cover, and they were black. The weird thing is that all my fish loved to eat my daphnia, but the new killies I got from him did not like them! I wondered if his black ones were more tasty or something. 

Fishfur- I am scared of starting another culture! Greg told me they need full spectrum lighting, lots of aeration, and sounds like fertilizing too! More plants! I am not sure. Maybe you can talk me through how to take care of them? Bill presents a good argument to feed them high quality food so that your fish get as many nutrients as possible. However maybe yeast is okay? It naturally has a very high vitamin B content right? Btw, I got the fresh yeast at Brandt's warehouse on Wharton Way/Dundas here in Mississauga. It's the German meats butcher/deli meats maker. If you've never been there, I would highly recommend it. They have all the European specialty foods plus an amazing butcher counter. Their prices are excellent. And it's a fun outing! They are only open Wednesdays to Fridays. They have a cafe too so you can sit down to a delicious plate of Wiener schnitzel or cabbage rolls when you are done shopping!

Jackson- what is happening with the dero worms and snails? Are the daphnia eating them? How are they surviving with each other with minimal food? Do you have a large culture? 

Scott- thanks for the offer. I have about 20 right now. I checked on them this morning and they are alive. I fed them dry yeast soaked in water and hopefully the population will grow again. It's going to be slow though.

Dominique


----------



## LTPGuy

SwimmyD said:


> Probably a hundred per square inch (counting all the babies). Massive.


This is an insane density! Understandably this is an estimation but you're telling me that you're seeing an opaque cloud of daphnia in your culture through out your container? Under the light source is a different matter.

I am wondering if overpopulation is also the potential cause of your crash. I've only read about two instances where a population may crash. Overpopulation and toxin.

If you needed so much daphnia, perhaps a larger container like BillD might be cool to have!

Thanks for bringing up the matter as we are all learning from these experiences.

Bill mention something which made me wonder. I did a quick google to get a second opinion on nutritional value. Here is an excerpt from an alternative source on nutrional value. This is not personal, but I think it benefit everyone to have a full picture. Perhaps Bill was referencing Artemia.



> The nutritional content of Daphnia varies with age, and what its been eating. The protein content is usually around 50% of dry weight. Quite the opposite from Artemia, adults normally have a higher fat content than juveniles, about 20-27% for adults, and 4-6% for juveniles. Some species have been reported to have protein contents exceeding 70%. Live Moina are about 95% water, 4% protein, 0.54% fat, 0.67% carbohydrates, and 0.15% Ash. The fatty acid composition of food is important to the survival and growth of fish fry. Omega-3 highly saturated fatty acids are essential for many species of fish. Moina cultured on bakers yeast are high in monoenoic fatty acids. By using what is called w-yeast (yeast enriched with cuttlefish oil), Moina will contain very high levels of Omega-3 fatty acids. Moina can take up lipids very easily from the emulsion, but there is a side effect to this, apparently it also slows productivity, so this emulsion should only be fed to a batch separate from the main growout colony. Commercial formulas are available in pet supply houses for the enrichment of Artemia, Rotifer, and Daphnia cultures.


Excerpt taken from here.
Other references...
http://www.caudata.org/daphnia/
http://ribarstvo.agr.hr/volumes.php?lang=en&search=Article:25

And this is an lengthy, but awesome read about culturing daphnia, procedure, setup, recipe, and experiment to optimize the culture.
http://ribarstvo.agr.hr/volumes.php?lang=en&search=Article:25.

In the footstep of the Great Mr. Mando, I've got daphnia to spare if anyone needs them. I am in Mis'ga also. Mr. Mando is a much much nicer and "better" looking guy though.


----------



## Scotmando

SwimmyD said:


> Thanks again everyone,.
> 
> Btw, I got the fresh yeast at Brandt's warehouse on Wharton Way/Dundas here in Mississauga. It's the German meats butcher/deli meats maker. If you've never been there, I would highly recommend it. They have all the European specialty foods plus an amazing butcher counter. Their prices are excellent. And it's a fun outing! They are only open Wednesdays to Fridays. They have a cafe too so you can sit down to a delicious plate of Wiener schnitzel or cabbage rolls when you are done shopping!
> 
> Dominique


I was at Brandt's on Thurs. I love this place. Being Dutch, I grew up on Germanic style foods & Brandt is the goto place for deli items including cold cuts, sausages, 'rollmops' (pickled herring)' candy, dill pickles etc. They are beside their processing facility. Prices are awesome. Their products are also avail in grocery stores at 'retail'.

I did not know the had active yeast!



LTPGuy said:


> In the footstep of the Great Mr. Mando, I've got daphnia to spare if anyone needs them. I am in Mis'ga also. Mr. Mando is a much much nicer and "better" looking guy though.


I'm thinking you want me to bring a big bowl of the 'Bhut Jolokia' Guacamole to the BBQ! Only if you like my florist shop VANDERFLEET on Facebook



Fishfur said:


> Well, if you need some green water I can sell you a culture to start with.. I have some going now. Let me know..so long as you keep reculturing it will carry on for a long time. You can refrigerate portions to maintain them alive longer too, if you have a bit too much on hand once it gets going.


I bought my greenwater from Karen a.k.a. Fishfur. It's all I feed my Daphnia. I culture it in 2x 1.5litre bottles with a rigid clear plastic tube attached to an air hose with a medium bubble stream to keep the water active. I top up with boiled (cooled off) water to keep the culture pure. I also feed with the Guillard liquid algae ferts Karen sold to me.

Here's a photo of my Nannochloropsis Algae Culture a.k.a. "Greenwater"


----------



## Fishfur

Scott, great idea with the rigid tubing.. wish I'd thought of that !

Algae cultures are not that difficult to maintain, at least I don't find them so. But Greg's right, they do need a very bright light source for at least 14 hours daily. Mine get 14 - 16 hours here, but 18 hours is better still. I use my light garden to grow algae, but I don't want it on for 18 hours. It's not good for the succulents. 14 hours has worked well this winter.

Either a 65 or 6700 K tube in a fixture or a 23 W daylight [ Phillips Daylight 6500 K] spiral in an inexpensive clamp fixture with an aluminum reflector on it, which Home Depot has for about $15., should work. In summer, leaving the bottle where it gets all day sunlight will work, but it's slower. Lights do need to be quite close to the culture, and a simple timer takes care of the on/off cycle.

Other main requirement is food, but very, very little is needed. I use a type called Guillard F2 liquid that ReefCrew sells because it's designed specifically to grow liquid algae and I don't have to worry about undissolved salts from dry fertilizers which might have adverse results if injected into a tank of shrimp. But many do use basic balanced dry ferts for this. Say, 20-20-20, but you'd have to be careful of dosage, which is why I pay for the Guillard instead. One bottle of Guillard lasts a very, very long time. Single dose per culture, one dose is less than 2 mls. If I used dry stuff, I'd probably dilute it at 1/4 the label's recommendation and use that, well dissolved, and see how that went. Can always add more if needed.

I also use distilled water because it's sterile to start with.. and I have a small distiller, but it's not essential. Boiled tap water works, as Scott said. Ten minutes in a nuker will also sterilize water.. I find that a blasted nuisance to do though. Or you can not bother with sterilizing at all and mostly get away with it, just dechlorinate it. I prefer to err on the side of safety, and since I have the distilled on hand, that's what I use. You can certainly buy it, discount grocery stores have it for around a $1 per 4 litres. Drug stores are a rip off, charging more than $2.49 for the same water.

There is not a lot to it. Take the existing culture, divide in half. Use one half to feed - keep any left over in fridge to maintain it for a couple of weeks. Pour one half into a new container with new water, fill nearly full. Add fertilizer. Drop in the air stone, which needs to be near or on the bottom & leave it running 24/7. Artificial lighting, minimum 14 hours, or all day sun in summer.

I use gallon bottles that distilled water came in originally, which take a wee bit longer to grow than smaller vessels do. You can use any size container you wish. 2 litre pop bottles are popular. For aeration, I use plastic stones that come weighted, so they stay down without an argument and are easy to clean when they get gummy. They also appear to last almost forever, unlike composite stones. Run as much air as possible without overflowing the bottle.

I have a light garden I built many years ago, already on a timer, so I've used it. I put the algae cultures right beside it. They only get the reflected light, not direct, but there are 10 tubes up there, all 65 or 6700 K, so despite it being rather indirect, it works. New culture is ready in about ten days.. when you can't really see your hand through the bottle, it's ready to feed or split for a new one. You don't have to make as much as I do if you don't need it. I've wondered about freezing it.. but have yet to try that.

It can crash.. any culture can.. but usually it happens when I've forgotten to split it in time. It can get too dense eventually.. or it runs out of food and will begin to lose colour. But even then, more often than not, adding fresh water and a second dose of ferts will revive a crashed culture. If you want it to remain as pure as possible, cover the bottle top to prevent wild spores from entering. I don't worry about it much.. so far, no real big problems. Extreme summer heat last year in this apartment crashed a culture beyond saving for me, but you should not have that problem in the house.

I sincerely look forward to trying to maintain my own daphnia culture.. I've tried a few times and lost them with errors I made. Hopefully I get it right next time.


----------



## BillD

Here are a few more things, some in reply.
The cysts look like bits of pepper. They are black and sort of triangular. You can see them in the daphnia, in the abdomen area when they are being formed. Otherwise they look pretty much clear. In my case the ring created by the cysts around the edge of the pool cover appear like ake a brown bathtub ring. When you look closely you can see the cysts.
One of our DRAS members when doing a presentation on culturing daphnia, said he fed liqified baby food, sweet potato or squash, if I recall. I was skeptical that they could eat this but the samples he brought, had clearly ingested something orange, so that is another food possibilty.
Nutritionally, if the daphnia are 50% protein by dry weight, which I wonder about unless their shell is protein, that would make them about 5% protein when alive. Again, from observation, when you feed large quantities, so the fish have food in front of them 24/7, growth is phenomenal. interestingly, fish will eat dry food even with daphnia present. Most will stop eating when full. The one exception is the betta. They won't stop eating until they are all gone.From observing the one I had, if you gave him 500 daphnia, he wouldn't stop until they were gone, and would pass incredibly (seemingly impossibly) large stools.
In every case, the large amount of bulk provided by the exoskeleton of the daphnia, allows the passing through the digestive tract of this huge amount of food, without any issues, even with mbuna. This has been my experience.
For anyone looking to get a starter culture, or catching enough to feed their fish, almost any small body of water can host them. Even temporary spring ponds, ditches or flooded areas can have them. You want to find a body of water that contains no fish. Storm water retention ponds seem like a likely source these days, especially if waterfowl visit them. I have several within a couple of miles of my house. 
Economically, it is too expensive to travel any distance to acquire any, but any bit of water near you is worth checking, however small. Seeding these areas may also be worthwhile, for the future.


----------



## Fishfur

I'm guessing a stream wouldn't be a good spot ? There's one running in the park up the street.. might be worth checking I suppose. Wonder what species the local ones are ?


----------



## BillD

A stream isn't usually a good spot, but I have seen them in the mouth of a large creek opening into a marsh, along the edge where there was little current. While not the best spot, it may be worth checking. You only need a few to start a culture.


----------



## LTPGuy

BillD said:


> A stream isn't usually a good spot, but I have seen them in the mouth of a large creek opening into a marsh, along the edge where there was little current. While not the best spot, it may be worth checking. You only need a few to start a culture.


I've tried streams, ponds, small lakes, lake ontario, puddle near the lakeshore, pond and puddles around Mississauga without any luck. I've gotten a lot of mosquito bites though!

The other problem with collecting wild culture is that you might get more than what you've bargain for. i.e. Hydra, parasite, larvae, nematoes, etc

I wonder if it is because of the mosquito spray in the city that's keeping the daphnia away as I have no luck at all in Mis'ga, and trust me, I've tried and tried.

Fishfur/Scottmando, is there any differences or anything special about the algae in your green water? I started mine from old tank water, and they get quite glow in the dark green with good lighting.


----------



## Scotmando

LTPGuy said:


> Fishfur/Scottmando, is there any differences or anything special about the algae in your green water? I started mine from old tank water, and they get quite glow in the dark green with good lighting.


The 2 bottles have the pure Nannochloropsis oculata algae culture. I only used boiled water and keep the lids on the bottle with a hole drilled just for the rigid air tube.

The algae culture in the middle is just from tank water. They look the same green colour. I'll have to look at the cultures with my microscope to see the difference.


----------



## SwimmyD

Hi everybody, sorry about dissappearing for so long! It's been totally crazy around here.  However I survived the week! 

So I think my problem was the density (yes! It was daphnia soup!), combined with killer mould. So I started all over again with my 20 or so survivors, and a few inches of water on the bottom of the 5g tank. I fed them the dried yeast every 2 days, and of course- the slime on the bottom started again. Ewwww

I convinced Greg that we needed to get to Brandt's again, so I could get more fresh yeast. Started feeding them that stuff on Friday. Well, today the population has blossomed! . I can see thousands of baby daphnia swimming around! So. I'm going to be smart this time. I've cut up the fresh yeast into small portions. Apparently you can freeze it with no ill effects! I will watch it closely to make sure there is no mould, and I will most definitely keep the population down by either over feeding my fish (LOL) or freezing it. Then I will start a backup culture in a small container if I think the population is getting up there. 

Finally, I'd better get some green water going. I just need some time for this. Greg and I are cleaning up the basement atm. Cleaning things up for ourselves and the shrimpsters bbq. I'd like to set this green water up near my brine shrimp hatchery (which I haven't started yet). 

I have to agree with LTP guy about the other critters you might bring into your tank when harvesting from the wild. I would worry about that. Fishfur- I think you have to hijack somebody's pool cover to be safe! Plus there are so many chemicals in municipal bodies of water. All the runoff from city streets bringing fertilizers, dog poop, salt,and any chemicals that people intentional dump down the city sewers because they don't know what to do with leftovers) (people do that all the time!). That's why there aren't any frogs left in local streams etc. if you were in more rural area, I think you would be okay. 
Thanks!


----------



## Fishfur

I'd forgotten 'till LTP mentioned it, but Miss'ga does do massive mosquito control in the parks and such places.. chances are good that also does in all kinds of other critters as well, like daphnia. Chances of finding them are not very good, even given the risks of other creatures coming with them. Though if you culture them carefully and take out only daphnia to reculture you can get rid of most other crittters with a bit of time and care. Mosquito larvae are usually taken eagerly by fish, so you just feed them and that's them done with. Other species, like rotifers or copepods, could also be cultured separately if you wanted to take the time and effort to separate them out. Once they've been recultured a couple of times, I would expect most contaminants from the original environment to be vastly reduced, or gone completely. Though I must admit, some contaminants are certainly persistent, such as heavy metals and a few other things, but what guarantee do you have that any culture would be entirely free of such things ?

And as Scott said, the culture I use for greenwater, which he got from me, begins from a laboratory propagated pure disc of Japanese Chlorella.. Nannochloropsus species. If cultured carefully you can keep it virtually pure chlorella, and the main advantage to it is that you won't get other algaes, such as the hair types, growing in it. 

It is pure single cell free floating algae of a known size.. not more than 4 microns, so when I feed it, say, to shrimp zoeys, I have a fair idea if it's a size they are able to consume or not. Not all species are the same size.

It also has another advantage. It's one of the only species that will grow in either salt or fresh water. Most others require one or the other.


----------



## dock

SwimmyD said:


> Hi everybody, sorry about dissappearing for so long! It's been totally crazy around here.  However I survived the week!
> 
> So I think my problem was the density (yes! It was daphnia soup!), combined with killer mould. So I started all over again with my 20 or so survivors, and a few inches of water on the bottom of the 5g tank. I fed them the dried yeast every 2 days, and of course- the slime on the bottom started again. Ewwww
> 
> I convinced Greg that we needed to get to Brandt's again, so I could get more fresh yeast. Started feeding them that stuff on Friday. Well, today the population has blossomed! . I can see thousands of baby daphnia swimming around! So. I'm going to be smart this time. I've cut up the fresh yeast into small portions. Apparently you can freeze it with no ill effects! I will watch it closely to make sure there is no mould, and I will most definitely keep the population down by either over feeding my fish (LOL) or freezing it. Then I will start a backup culture in a small container if I think the population is getting up there.
> 
> Finally, I'd better get some green water going. I just need some time for this. Greg and I are cleaning up the basement atm. Cleaning things up for ourselves and the shrimpsters bbq. I'd like to set this green water up near my brine shrimp hatchery (which I haven't started yet).
> 
> I have to agree with LTP guy about the other critters you might bring into your tank when harvesting from the wild. I would worry about that. Fishfur- I think you have to hijack somebody's pool cover to be safe! Plus there are so many chemicals in municipal bodies of water. All the runoff from city streets bringing fertilizers, dog poop, salt,and any chemicals that people intentional dump down the city sewers because they don't know what to do with leftovers) (people do that all the time!). That's why there aren't any frogs left in local streams etc. if you were in more rural area, I think you would be okay.
> Thanks!


I want to try out the fresh yeast like SwimmyD does, simply because feeding the culture with dried yeast alone doesn't yield much daphnia, at least not in my case. I haven't gotten any daphnia to feed my fish for the past 2 weeks.

I'd like to prepare my next setup before getting fresh yeast, and I have a few questions in mind. 
Will bigger tank size, like 30g be better and produce more daphnia? Isn't it the case that bigger surface area be better? I question it because I see members here are using bottle and vase. How about light? Will light for 12 or more hours be a bad idea? Has anyone tried feeding daphnia with soy flour or paprika?


----------



## Fishfur

Flour will just cloud the water and kill the daphnia. Paprika likewise. Neither would provide anything like a balanced diet in any case. Too high in carbs, not enough of the right fats, vitamins or minerals. Though soy is high in plant proteins, I would doubt they'd be able to eat it no matter how finely ground it might be.

Their preferred diet consists largely of single cell algaes, which are highly nutritious, quite well balanced for these creatures. Yeast is a substitute that will work. It is reasonably nutritious and they can eat because it also has very small cells. Nutrients are important not only for the daphnia to grow and reproduce but also so they themselves provide nutrition to whatever eats them. Most species of daphnia are filter feeders, so they also consume such things as bacteria and the very small creatures that make up what we call infusoria - which are varied and thus also provide a good balance of nutrients.

They do best in clean water. Though they've been known to survive some fairly awful conditions, you can't rely on them to survive poor water quality.

I am not sure about a larger tank to start with.. you'd need a fairly dense population for them to be able to find food in an overly big tank. They are very tiny animals, so you'd need to add a lot of food for them to find enough. That would also cause water quality problems. 

I would think you would do better to begin with a small tank, 2.5 G or so, and once it's well filled, maybe then move to a larger size.. maybe a 5 or 10. It's also a good idea to have more than one culture, because daphnia are prone to 'boom and bust' population cycles. They do produce a 'resting' type of egg, the cysts that were referred to in an earlier post, which can survive 'til conditions are better, even if that's next year. They are also sensitive to summer's heat, which can crash a culture. So having multiple cultures is a better idea than having one huge one, as you're more likely to have at least one survive if another does crash. And with multiple cultures you'd be able to harvest from them all in turn, so numbers would not drop too much in any given one.

I don't think they need that much light for themselves.. but the algae they live on needs a lot of light. If you were growing single cell algae along with them, the algae would need at least 14 hours of light. To culture algae you need to expose it to at least 14 hours of intense light a day, 18 hours is even better. But since you're feeding them, not growing algae with them, then 12 hours is more likely to get you green tank walls. If you don't want hair or other solid types of algae growing on the tank walls, I'd think 8 hours or so is enough.

Edit*. the 'resting' egg I referred to is called the ephippia.. sorry, should have looked that up sooner.


----------



## LTPGuy

Fishfur said:


> And as Scott said, the culture I use for greenwater, which he got from me, begins from a laboratory propagated pure disc of Japanese Chlorella.. Nannochloropsus species. If cultured carefully you can keep it virtually pure chlorella, and the main advantage to it is that you won't get other algaes, such as the hair types, growing in it.


I am unsure of your setup, but if it is similar to Mr. Mando, I wonder if spores can contaminate your culture from the air that you're bubbling into the culture?

Also, any result from looking under the scope Mr. Mando?



dock said:


> I want to try out the fresh yeast like SwimmyD does, simply because feeding the culture with dried yeast alone doesn't yield much daphnia, at least not in my case. I haven't gotten any daphnia to feed my fish for the past 2 weeks.
> 
> I'd like to prepare my next setup before getting fresh yeast, and I have a few questions in mind.
> Will bigger tank size, like 30g be better and produce more daphnia? Isn't it the case that bigger surface area be better? I question it because I see members here are using bottle and vase. How about light? Will light for 12 or more hours be a bad idea? Has anyone tried feeding daphnia with soy flour or paprika?


Patience young Jedi! It takes 6-10 days for daphnia to reach maturity. From which point, female produces a new clutch every 3-4 days. Each clutch contains 3-6 eggs. Assume one don't start feeding from the culture, you're looking at 3-4 weeks to get a decent population from ~20-30.

Fishfur has a point about increasing your holding tank slowly as you would likely add more food that would be wasted in the larger holding for the initial population.

A weirdo posted some links in post #11. There's a links to various recipes and which on produce the best population for the price.

For me, dried yeast is cheap and convenient. So is greenwater! I also don't have a of fishes!


----------



## bettasandbeads

*Daphnia*

Very interesting guys.
I haven't had much luck maintaining a culture, so will try you method.
Funny thing is I picked up a culture when I was at the CAOAC convention in Edmonton this weekend.
A plant guy was deminstrating benifits for Daphnia. It is a different strain then we have here. Larger and brown in colour.
Have set up a small tank with green water ( I brought back - his culture) and water from one of my tanks.
Also filled a 2L pop bottle with tank water, added some green water and have set it out side. Hope to be able to get my own green water growing.
Question? do I need an air stone? The guy in Edmonton said not to use one since he found it made the water too turulant.
Catherine


----------



## Fishfur

My set up is simple. I use four litre or one gallon distilled water bottles with airstones, lightly covered, beside a light garden with, IIRC, ten 65 or 6700 K tubes running 14 hours daily on a timer, to provide the needed light. I use liquid Guillard fertilizer, which is what the lab recommends for growing the algae. You don't need that many tubes, btw, it's just what I use to grow my succulents under lights, works for the algae too.

Fwiw, the pure strain discs I use specify using an airstone at all times. Don't have to run at full speed but enough to keep the water turning over. It prevents the cells from settling. If they settle, they don't get light exposure on all sides, slowing growth. If they settle and get covered up with more layers of settled cells, the ones on the bottom might die off, and they won't get enough light to continue division, to produce more cells. 

I would also not use tank water because you're bound to introduce undesirable types of algae strains, as well as bacteria, fungal spores, possible parasites. My cultures are about as pure as you can hope to get without taking quite stringent measures to ensure there's no contamination by anything else. Incidentally, I'm also trying to grow greenwater from tank water, just to see what happens.

However, if you want the purest possible culture, start with sterile water. I use distilled, which is as close as I can get to sterile without making myself crazy. You should use sterilized bottles, air stones and tubing, and ensure the culture container has a sterilized, tight lid. You would run the air line tubing through the lid so it's as airtight as possible, much as you would for a DIY yeast bottle, as Scott has done. It is the only practical way to limit entry of airborne spores or cells to the bottle while it cultures. And even going to this length, you will not be guaranteed a totally pure culture because you are not working in a sterile laboratory setup. The kitchen or fish room is far from sterile and air everywhere has spores, cells and other contaminants in it all the time.

Using a pure strain algae disk to start with, as I do, first, you cover the cells in the petri dish with sterile water and replace the dish cover. Expose it to light for 24 hours. Remove cover, use a sterile cotton swab to gently rub the now moistened algae cells off the nutrient agar agar gel in the dish. Pour the loosened cells into the sterile container full of sterile water, rinse off the cotton swab in the water to get as many cells as possible into the water, then add the fertilizer, place the air stone and tubing, close the bottle. Place in your brightly lighted location for at least 14 to 18 hours daily and run the air pump 24/7. In approximately 10 days you should have a culture dense enough to use, either to feed or reculture. If you can barely see your hand on the other side of the bottle as you look through it, it's ready. You should wear sterile gloves too, if you are really determined to get as pure a culture as possible.

If you plan to reculture and want to maintain a single pure strain, you have to use all sterile equipment every time. I do not go to this extreme. I wash my hands well. I cover the bottles loosely to keep out dust and dirt while they're running. And I have found that if they have any dead or dried out algae left inside after I empty the culture out, the easiest way to clean that off is to submerge the bottle in one of my tanks and let the Otos and snails eat it. Takes them a few days and they do a much more thorough cleaning job than I can. Then I wash the bottles in bleach water, rinse well, and dry completely before I use them again. Snail/Oto cleaned bottles look brand new after I've washed them out.. it's quite surprising just how good they are at getting every speck of dead algae out of a used bottle. They will even loosen hard water deposits, which then rinse out without effort.

I did try to rinse a bottle out with boiling water one time, but I learned that plastic bottles shrink and distort into op art in boiling water, much as some plastics will do in a dishwasher. Hence the bleach method. 

**But this is why I do not claim my cultures are 100% pure chlorella ** because I really can't guarantee that, no matter how much care I might take. I don't have a lab, and thus I can't be certain no contaminant has gotten in. 

But I have never lost a culture to any contaminant. I've never had mould,mildew or any other fungal issues. Losses have been due only to extreme heat or complete lack of food, if the culture is allowed to run too long. If it's food related, the culture can usually be revived by adding another dose of fertilizer.


----------



## bettasandbeads

*daphnia*

where do you get your fertilizer?


----------



## Fishfur

I buy it from ReefCrew.. same place I get the algae disks. It's not cheap, by the time you add the shipping but one bottle lasts for a very, very, very long time. Depending how often you culture, lasts six months or more.


----------



## SwimmyD

Hey Fishfur,
Can you please bring me some green water and a starter thing of fertilizer on Saturday? Whatever I need to get a culture going? My daphnia were doing really well, and Greg moved them into the basement. Well out of site, out of mind. The yeast is in the fridge upstairs. And I keep forgetting to feed them! Argghhh! Was up to thousands and lost a whole bunch again! But if the green water is beside them - I can feed them immediately instead of going upstairs and getting side tracked with other things....like forgetting what I came upstairs for and doing something else.....


----------



## SwimmyD

*Finally - a new culture starting*

Well its been quite some time since I last had a culture of daphnia. Then killed it. Then started again. Then killed it. This time though...its gonna work! Got myself some daphnia pulex- which are smaller than Igor's magna, but will do just fine as killifish food - although not for my blue gularis.

Got the culture while in Milwaukee, Wisconsin - it was fresh collected from an outdoor pond. The daphnia were a lot weirder looking than the ones I had been growing here. All the little daphnia had little black pepper like spots on them. And the spots were shedding onto the sides of the glass. I looked it up, and happy to say that those things are the "ephippia" which are saddle shaped cases that the daphnia can store eggs in. BillD had talked about these earlier in the thread, but I had no clue what they looked like. They do this when they know they are going to die -from drying up, overwintering, etc. So my pulex were getting ready to over winter in Wisconsin.

The cases can withstand great environmental stress. When things are good- they will hatch out. They already started hatching out in my new tank. There are a lot less than compared to just a few days ago!! Daphnia also reproduce by storing eggs and larvae in their pouches and releasing them live as they mature. This produces lots of daphnia in a short time frame.

So the good news is that daphnia pulex are harder to kill. They are more tolerant of most things- including temperature swings, higher temperatures, foul water, etc. I'm feeding them fresh yeast again, and it seems to be working. I've also got them in my kitchen again (yes - eewwww), but I can keep a better eye on them.

So I thought I'd post a picture of these daphnia and their numerous epippia, so everyone can see what they look like. Apparently all epippia look the same for all kinds of daphnia. And, if your culture crashes (like if you go away for a week and forget about them), then you can start a new culture using the mulm on the bottom of your tank. Who knew?? PS - the cloudiness is from the fresh yeast I just added. Just enough to last until the next day. Its the best way to keep the stink and scum to a minimum.


----------



## Fishfur

Way cool. Hope they prosper and that you may be able to share or sell some once they get going.


----------

