Green water & Daphnia

["Stephen Pushak" <teban at powersonic_bc.ca>]

Green water is a tricky culture to maintain, at least for me. When you don't
want it you have it and when you want it, its hard to get it going. I'd be
interested to hear others comments upon how to culture it.

Once you have a good culture of it, its not difficult to feed it; as Paul
suggests, some fish and plenty of fish food with bright light seems to help.
I think its important to keep the oxygen levels in the water high because if
you don't, you can sure end up with a cyanobacteria problem instead of the
green water. It also helps to start with a good culture. For some reason,
green water cultures don't seem to start spontaneously for me. I think you
need to have fish in a green water culture to control the growth of
infusoria which can prevent the green water algae from reproducing to a
sufficient population.

The Killie people here in Vancouver area have good luck raising massive
crops of Daphnia by feeding with yeast. Not every culture is a success so
there maybe some unknown factors such as pH. The guy who did the best also
started out by seeding his outdoor kiddie pond with manure & a little lime I
think. He buried a kiddie pond in the ground outdoors under partial shade of
some evergreens trees and controlled unwanted growth & slime by just washing
the excess over the edge of the pond with a garden hose. Of course, he also
had some mosquitoes breeding in there but the mosquito larvae make excellent
fish food too. Not every wife is as understanding about mosquitoes.

I've seen other people culturing Daphnia indoors in aquariums but the crops
are always very slim. I think there is a real knack for knowing how much to
feed and a certain among of serendipity too. Green water is a good food for
Daphnia because you can't over feed but I'm not sure if its best if you need
to maintain a huge Daphnia colony because of the amounts that you would need
to produce. Feeding a heavy green water culture might be just as tricky as
feeding a big Daphnia colony because it can crash too. I suspect it helps to
have tap water with a good amount of calcium already in it.

> Date: Sun, 8 Dec 2002 09:13:09 -0600
> From: Paul Krombholz <krombhol at teclink_net>
> Subject: Re: Daphnia feeding
>
> Green water is the best food for Daphnia.  It is less
> oxygen-consuming than bacterial cultures, and can be produced in
> large quantities by keeping a brightly lit guppy tank with few or no
> plants.