And yes the appearances of two Ostracods and Cyclops and even Dero type
worms in my Daphnia cultures (over the years) do make one consider the
possiblity of spontaneous generation. :)
I would fill one of those 15 gallon feed troughs with a couple "clean" fish,
aquarium water and use them to generate green water. That culture can be
placed in as sunny a spot as is safe for the residents in terms of over
heating. Once the green water is going, up to 50% of it a day may be removed
to feed your daphnia cultures. Replace that water with "seasoned" tap water.
Given light, water changes and organic waste from fish (who wander away less
frequently than apple snails) green water does a remarkably quick job of
In time that water changing will force equally healthy water changes on the
daphnia cultures as water must be removed to make room for the greenwater.
If you recall the indoor tank that went green and how water changes
(frustratingly) only encouraged it, you may recall how this works.
If leaves, dead insects and other flotsam and jet same blow into daphnia
cultures, so much the better up to a point. If all daphnia containers can be
placed under trees they will not cook in the midsummer sun and be as likely
to be depleted of oxygen. Also, if the daphmia are shaded, they will not
flash reflections towards the sky where they will be a magnetic draw for all
sorts of predatory insects which may either settle in (water beetles or
backswimmers for instance) or lay eggs (dragon flies, damsel flies...).
You will still get a few vegetarian blood worms (leave litter pending) and
the very predatory, but small, glassworms - especially later in the summer.
Start a back up culture in the other 15 gallon trough. It wouldn't hurt to
have a back up greenwater culture too. All those cultures will crash from
time to time. Having multiples gives one a chance to avoid complete stops in
If an out door culture crashes, it will almost always come back. However the
comeback may not be until colder fall weather. Native Daphnia can produce
well even with a little ice on top, if it is removed from time to time.
If the cultures are as cool as can be and if the Daphnia population is
allowed to remain pretty dense, they will consume most of the mosquito
larvae which hatch from those mossie egg rafts which look like small pieces
of charcoal scrapped out with fingernails. That way, the tiny mosquito
larvae become a part of the culture's food chain and don't hatch out
elsewhere. (At about 68 degrees the mossie larvae go on hold and seems to
just hang around waiting to be netted with a fine mesh net such as those
sold by Jonah's Aquarium.) Of course those eggs rafts can be collected and
left in fry tanks too. :)
It may still be necessary to sit down on an inverted bucket, net in hand,
collecting jar handy, and skim off the few mosquito larvae which grow up. I
spent 15 minutes doing that the other day. The times demand that we strive
to not raise mossies which can escape to the neighbors. The top feeders in
lightly planted tanks thanked me for the larvae.
All the best!
> I'm starting to believe in spontaneous generation.
> A couple of weeks ago, I brought a 55 gallon tank outside to clean it.
> After cleaning it, I neglected to bring it back in. Then, it rained 8
> inches last week. Along the way, a bunch of algae grew in the tank.
> Tonight, I was checking the tank to see if any mosquitos had laid eggs
> in the tank.
> They hadn't but the tank is chock full of daphnia. Two weeks ago, this
> tank was totally empty and very clean.
> I would like very much to maintain a culture of daphnia in the fish room
> as a source of food for my pygmy sunfish and any juvenile fish that I am
> fortunate enough to breed.
> Any ideas on how to set this up? I have a couple of 15 gallon cattle
> feed containers that I would be more than willing to use.
> Geoff Kimber
-- > /"Unless stated otherwise, comments made on this list do not necessarily > / reflect the beliefs or goals of the North American Native Fishes > / Association" > / This is the discussion list of the North American Native Fishes Association > / nanfa-in-aquaria.net. To subscribe, unsubscribe, or get help, send the word > / subscribe, unsubscribe, or help in the body (not subject) of an email to > / nanfa-request-in-aquaria.net. For a digest version, send the command to > / nanfa-digest-request-in-aquaria.net instead. > / For more information about NANFA, visit our web page, http://www.nanfa.org /----------------------------------------------------------------------------- /"Unless stated otherwise, comments made on this list do not necessarily / reflect the beliefs or goals of the North American Native Fishes / Association" / This is the discussion list of the North American Native Fishes Association / nanfa-in-aquaria.net. To subscribe, unsubscribe, or get help, send the word / subscribe, unsubscribe, or help in the body (not subject) of an email to / nanfa-request-in-aquaria.net. For a digest version, send the command to / nanfa-digest-request-in-aquaria.net instead. / For more information about NANFA, visit our web page, http://www.nanfa.org