# Cultivating food



## qwerty (Dec 15, 2009)

Hi, I'm interested in cultivating daphnia and algae.

2 questions... 

It sounds like daphnia is fairly simple, all you really need is a container or two, some yeast, and some green water... Manure in a cheesecloth is supposed to make a huge improvement in the culture... Does this have to be fresh manure, like from a farm? Or can I use manure purchased from a garden store... (Hmmm, I wonder if the high park zoo would let me take a shovel full, lol)

As for the algae... The basic principal of growing it is simple, the problem is knowing what kind I want to be growing... I've been getting my information from The Enclyclopedia of Live Food, and while it gives guides on what factors will influence the type of algae growth, nowhere does it give a list of which algae is recommended to grow. It does however mention that hair net algae will be likely to invade an aquarium if introduced as food... Anyone have any experience with cultivating algae want to fill me in?


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## Darkblade48 (Jan 28, 2008)

I have never heard of adding manure in order to culture Daphnia. I have always read that they require green water to feed on.

Usually, this can be done by just dumping some phosphates into a bucket of water, putting it near a window that receives sunlight, and waiting.


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## qwerty (Dec 15, 2009)

Pretty sure you can also leave a piece of lettuce in a jar of water by the window to get green water as well...

But yes, apparently manure wrapped in a cheese cloth and left in the yeasty water makes a huge difference in the size and health of a daphnia colony.


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## bae (May 11, 2007)

That free rainbowfish ebook that I posted the link to a couple of weeks ago has a very large section on cultivating live foods, including green water and infusoria.

The manure recommended for daphnia is for large outdoor projects. The manure feeds algae and protozoa and the daphnia eat both. I wouldn't use either fresh or composted manure indoors. 

I put buckets of water with some grass clippings or compost on the patio in summer to lure mosquitos to lay so I can confiscate their larvae for my fish, and most of them don't develop green water, unless it's the larvae that are eating the algae. If you want to start a culture indoors in winter, you might need a starter. You can't count on algae spores floating around your house, but aquarium water may have have some. I wouldn't get concerned about pure cultures unless you're raising marine algae. Unless you use some elaborate procedures, your cultures won't stay pure. Just raise what grows for you, and a mixed culture of local wild species will be more stable than a pure lab culture.

I've had filamentous algae, but I've never had a problem with it, although many people have. I think it's rather pretty, like extremely fine moss. I've got a steadily increasing wad of it in a gallon jar I'm raising some killie fry in. It must have come in with the java moss I put in originally, so I must have it in my other tanks, but I never see it there. I suspect it's the high nutrient levels of this heavily fed jar that's encouraging it.

There are a lot of systems for raising daphnia indoors. The most effective seem to involve feeding yeast or pureed vegetables (baby food) rather than algae. I'd like to try it some time, but it seems to involve a fairly large volume of water in a number of containers and a fair bit of close observation and experience to avoid the culture crashing.

I raise microworms and related nematodes, white worms and flightless fruit flies for my fish. These cultures are pretty easy and reliable. Mealworms are also easy, but none of my fish like them much -- I used to have a lot of frogs and geckos that I raised the mealworms for. Unlike white worms, earthworms and nematodes, mealworms (beetle larvae) rapidly drown so you can really only feed them to fish that like them.

The size of food a fish will eat depends more on the size of its mouth than the size of its body. I'm raising some killifish now, which have very large mouths, and it's amazing the size of worm a tiny fry can successfully eat. On the other hand, I have full grown Julidochromis going crazy for microworms and decap brine shrimp eggs. The fish may be 2 1/2 inches long, but they have small mouths.

Note also that there are worms of all ages/sizes in a culture, so even if a fry can't manage the adults, it can eat the younger worms. If you keep a few ramshorn snails in the fry tank to clean up uneaten food (dead worms) it's no problem. And then you have lots of spare snails to crush and feed your larger fish.

If anyone wants starters of any of my cultures, let me know. I'm looking for grindal worms, just like everybody else... I've got microworms, walter worms, banana worms, white worms, flightless fruit flies, and MTS and ramshorn snails.

I've also got a gallon jar on the window sill with water and sediment from a patio bucket that held green water. The water is presently pale yellow, but I'm sure it's full of algae spores. It's also got a variety of tiny crustaceans (copepods?) in it, and it produced a lot of the flies that have bloodworms as their larvae. It's been interesting to watch, and if anybody wants some water or sludge from it, let me know.


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## qwerty (Dec 15, 2009)

Just sharing some information here...



> Filtered pond water, garden soil, and either cottonseed meal or soy bean meal are used as the ingredients for the production of Daphnia. The proportions are one quart water, three tablespoons soil, and one tablespoon meal. These are mixed together and allowed to stand at room temperature, covered, for five days. The mixture will "ferment", and a considerable amount of gas will be produced during the period. After five days, the clear liquid above the solids is poured off and filtered through muslin. The strained liquid, containing large numbers of coliform bacteria, can be refrigerated in a closed jar for future use. About two tablespoonfuls of the bacterial mixture will feed about a gallon container of living Daphnia.


There seems to be other even simpler methods that need just a hard boiled egg yolk, or milk powder, and from what I'm reading, it seems to be feasible to use containers as small as gallon jars... I'll have to keep reading around...

Btw, impressive Bae, sounds like you've got quite the little setup going... Must have some pretty well fed fish there.


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## BillD (Jun 5, 2006)

if you can grow green water, daphnia will reach huge numbers very quickly. It is sometimes difficult to keep a culture going as some species have a dipause, which means they lay cysts instead of live young. The cysts than need to ret before they will hatch. Keep in mind, that daphnia, as well as most live foods are about 90% water, so you need to feed huge amounts to be of real value as food. They are also better if they are gut loaded, which provides the extra nutrient of what they have eaten. I grow huge quantities each spring, and have found that dog crap makes excellent green water.


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## qwerty (Dec 15, 2009)

I used to cultivate crickets, so I know all about gut loading... Or at least the concept behind it...

Mainly I want to cultivate daphnia because it gives my fish something to hunt, and it'll survive on the surface of my water, rather than sinking to the bottom and getting lost in the tank. Also cause harlequin rasboras seem to like them...

I'm thinking of doing this in a set of 2-3 5gal aquariums, I'd use the egg yolk infusion at first to get things started, then may provide a bit more variety of food sources to the daphnia for gut loading once I see things establishing themselves a bit...


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## BillD (Jun 5, 2006)

Each spring I grow daphnia by the millions on the winter cover of my swimming pool. When conditions are right they multiply at an astonishing rate. While they may not be the best live food, they produce phenomenal growth rates. My fish have them in front of them 24/7 for a number of weeks until I open the pool. As an added benefit, there are numerous other aquatic insect larvae such as blood worms and glass worms in the culture.


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## igor.kanshyn (Jan 14, 2010)

*daphnia from a pond water*

I'm thinking about getting some water from a pound in a park. Keeping this water in a jar near a window should give me some daphnia living there. Will this work?

Also I'm afraid a little about getting some other creatures and harmful bacterias from a pond.

What do you think about this way to grow daphnia as a fish food?


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## BillD (Jun 5, 2006)

The pond has to have daphnia in it. You need lots of daphnia to be of any real value as food. They are 90% water. You might get a few growing in a jar, but consider that a betta can probably eat 300 to 400 at a time.


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## igor.kanshyn (Jan 14, 2010)

BillD said:


> The pond has to have daphnia in it. You need lots of daphnia to be of any real value as food. They are 90% water. You might get a few growing in a jar, but consider that a betta can probably eat 300 to 400 at a time.


Thanks for the answer. 
I'm planning to have it for fry.

And what about some other pond creatures that can be harmful for fish tank?


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