Daphnia Fishkeeping Tip 4


	Fishkeeping Tips 4: Daphnia

Keeping Daphnia can be easy, consistent and long term, but unfortunately, they are at first a slightly more challenging
    live food to maintain. Daphnia are a small Crustacean of the order Cladocera, sometimes called "water fleas" because
    of their rounded shape, small size and "hopping" swimming style. They are common in ponds around the world. I have
    found that they will thrive on a number of foods, and though they do best best in outdoor tubs, they can be kept in an
    aquarium indoors for extended periods. Daphnia are one of the most nutritious foods that can be fed to aquarium fish.

    Your success with them will depend on:

    1. The species you work with and whether it is a wild or a domestic line, (domestically bred lines prove to be more
         forgiving and crash less often),
    2. What you feed them- and I have a recipe I use below,
    3. How consistently you choose to maintain the water, and
    4. Whether you keep them indoors or out.

    My choosing to raise daphnia is a result of needing a food that can be raised in fairly large quantities, doesn't need
    to be refrigerated, doesn't get loose, is easy and inexpensive to feed, while being one of the most nutritious foods to
    feed. For me, the journey toward my now keeping Daphnia simply and reliably has been worth it, but getting started
    was a little tricky. My experience has been: There are more than one species of Daphnia, and many cultivated lines
    within those species, besides what are available to be caught in the wild. Some are available online through biological
    supply houses, some may be available from a local pond, and some can come from other hobbyists. I have the Russian
    Red Daphnia originally released into the hobby by Jim Langhammer. If you can find them, they are a hardy and prolific
    line.

    Often, daphnia simply brought home from the local pond will do OK as you get them started, but then will unexplainably
    "crash', where a slight change in feeding schedule or water temp or whatever may cause them all to die off suddenly.
    Keeping 3 or 4 groups going at a time helps this, but I have found that starting off with a hardier strain that has been
    kept by those raising them for the aquarium hobby leads to less frustration. I would expect that wild strains will do
    better in outdoor tubs, but I have not tried them that way. I raise most of my Russian Red daphnia in outdoor tubs,
    as that is the only way to produce enough for my needs.

    Personally, I have not been able to raise daphnia indoors in sufficient quantities to justify the tank space required,
    though I can keep them thriving. Many people routinely keep them indoors, and some raise them in fair quantities.
    Your success may vary, but when raised in tubs outdoors you shouldn't lose them once a feeding schedule that works
    for them is established, particularly after a season or two when they have come back for you in the spring. I keep
    some Daphnia indoors during the summer months by letting populations thrive in fry tanks- they will have young that
    are eaten, while the adults aren't bothered, and they don't bother the fry. I also keep daphnia going in small containers
    holding females about to drop fry as they don't foul the water and will survive for long periods, while eagerly eaten by
    the fish. And with each year, the daphnia that come back are gradually better suited to your environment.

    Daphnia are used to detect minute changes in water chemistry and are very sensitive to change or inconsistent
    water maintenance. The best way I know of to get Daphnia going is to fill a large (at least 30 gallon) trough or tub
    with water outdoors in moderate sun during the early spring. Add some manure- poultry manure is best, and let it
    break down and cause the water over a couple weeks to become green with algea. If you are lucky, Daphnia may
    appear anyway, but don't count on it. When the daphnia you wish to use is obtained, float them in a bag to adjust
    the temperatures, then release them to feast and multiply in the green water. As the water clears, introduce them
    to the Daphnia food mix. Do not overfeed. I usually add a few plants to help maintain water quality. Do not redose
    the manure.

    Let mulm build up on the bottom. I do not provide aeration or heat to my outdoor tubs. Keep water level up by
    adding clean, aged aquarium water and change out 10-15% of the water with seasoned aquarium water about
    no less than every 2 weeks from mid April to mid September. I will siphon out most of the bottom mulm about
    midsummer. They will overwinter, even when frozen solid- I have had outdoor tubs that froze solid, and the
    daphnia did return in the spring, provided the tub is not allowed to dry out (and even then they may reappear, but I
    have not allowed a tub to do that). My colony is now into its 8th year. (2015) For keeping them indoors, aeration is
    usually recommended with a sponge filter, regular water changes and strong light.

   Sparingly feed the mix daily, and keep two or three populations going. Never overfeed. With indoor colonies,
    keep the bottom of their tank siphoned clean, and do about 10-20% weekly water changes (because you are
    dealing with smaller tanks than the outdoor tubs, and as I mentioned, they are particularly sensitive to water
    changes). Experiment with feeding yeast occasionally, adding new food only after the water has cleared.
    Overfeeding is the main cause of population crashes. Use a more open mesh net to catch and feed the adult
    daphnia to get the most from the culture. They reproduce quickly, and mistakes can be easily recovered from if
    there are live individuals left. If it does crash on you, do a water change and wait. It is possible that hibernating
    cysts may come to life and restart your culture. If after a week you do not see any life, you will need to re-obtain
    another culture and start over.

   Never use fresh tap water for water changes, especially if it has not been dechlorinated- I always use clean
    aquarium water from a healthy tank nearby. Once I choose a tank to use, I always use water from the same
    tank. I had to try things a couple times to get it dialed in, but the result for me has been 100 gallon tubs that
    in the sunlight mid summer will show broad bright red balls of Daphnia a foot across to feed from. They,
    the red worms, brine shrimp and Vinegar Eels have proven to be the low maintenance, abundant, easy
    to harvest, no getting loose, biting, or disease carrying live foods I had hoped for.

                                                                Daphnia / Small Fry Food Mix

    A consistent supply of green water is always best, but in the quantities I'd need, an alternative is essential.
    This mix is what I am currently using, arrived upon over the last 5 years of testing what has worked best for me.
    You will notice I do not use yeast in the basic mix; but I alternate yeast and mix feedings, one every other day,
    and that has worked well.

    Mix together 1 cup regular flour, 1 cup soy flour, 1/3 cup Paprika, set aside. In blender or food processor, finely
    grind down a vitamin enriched spirulina flake food from a vendor such as Jehmco or Brine shrimp Direct to create
    1.5- 2 cups of very finely powdered vegetable food. Then mix the powdered vegetable flake into 1 cup of the flour mix
    until the overall color of the final dry mix is uniformly green. You will end up with about 2-3 cups of prepared food.
    Refrigerate the mix that's ready and freeze the rest for the next batch. I then put 2 tablespoons of this final mix into a
    16 oz. jar filled with luke-warm water, shaking thoroughly. I then add this water-based mix sparingly to the Daphnia
    tub with a turkey baster every other day, (about a baster full of food mix for each 100 gallon tub) shaking the mix
    thoroughly each day, which further breaks it down, until it has been used up. I feed active dry yeast- about 1/2 tsp. into
    a cup of warm aquarium water on alternate days. Let the yeast water sit for 5 minutes for yeast to "bloom", then stir
    and dose into tubs. Do not overfeed, allow to become only slightly cloudy. Keep the watered flour/spirulina mix
    refrigerated. I make a fresh batch about every 10-14 days based on the amount of Daphnia I am feeding. I will also
    feed the yellow/green water after the solid material has settled to the bottom of the mix to my really small egg layer fry,
    and the Daphnia mix as is to livebearer fry, eventually supplementing it with Vinegar Eels, then Baby Brine Shrimp
    as soon as the fry are large enough. (Update- 2015)- I no longer feed the daphnia mix to fry, but feed a finely ground
    mix of the ground green flake, a ground high protein pellet and a mix of crushed krill and freeze dried copepods.
    That is my fry mix.