The vexed problem of how to feed it to the fry is aperennial one. Do we
add the fry to the culture or the culture to the fry? My preference has
always been the latter because of the problems of handling delicate little
fry and the variation and unpredictable responses in water quality that
tend to occur in these cultures with frequent major losses. Using a
shellgrit substrate in your culture tank and some aeration and even gentle
UG filtration may help to stabilise conditions there without compromising
the culture. Remember it is a living mixture of organisms and should be
considered as a "community tnak with a difference". The organisms need some
attention to water quality, regular good supply, temperature, water changes
and above all light.
Over the years I have seen a variety of ingenious ways of feeding the
culture to fry. Remember the water in the culture may be very different in
pH, hardness, temperature, ammomia, nitrite and nitrate content (as well as
other parameters) so adding significant volumes to your fry can be
hazardous if not done carefully. Also there is the added worry of unwanted
pest and enemy species not obvious on inspection because of turbidity of
the culture. this is more of a worry if the source is from outside as it
often is because of the availability of the extra light from the sun.
The simplest method is to lower the water level in the fry tank to prevent
overflows, place the container of culture on the cover glass of the fry
tank and insert an airstone bubbling away in the culture to maintain a good
suspension, and then set up a fine syphon from the culture into the fry
tank. Airline with a control valve inserted to enable flow control is ideal
so that there is a gradual flow of food into the fry tankthat they can eat
at a steady pace, the excess organisms are less likely to die off enmasse
and pollute the fry tank, and the differences in water parameters are
neutralised by dilution. The end of the syphon in the container can be
attached to a styrofoam float for efficiency and the valve is easily
cleaned in the case of blockage all for a minimal price.
The principle of "plankton ponds" for raising fry to small fingerling stage
is well established in aquaculture and the quality of the fry raised on the
variety of nutrients in the multiple organisms in GW cultures is usually
obvious.
The ease of feeding with substitutes that are conveniently available in the
form of APR and other micro-encapsulated HUFA's etc is so seductive that we
often forget the "grass roots" of the hobby such as greenwater.
Thanks for reminding us Adrian
Regards,
Bruce.
Bruce Hansen, ANGFA, caring for our aquatic ecosystems.
Please visit us at http://www.ozemail.com.au/~fisher/angfa.htm
----------
> From: Adrian R. Tappin <atappin at ecn.net.au>
> To: rainbowfish at pcug.org.au
> Subject: [RML] Phytoplankton
> Date: Tuesday, 17 March 1998 8:19
>
> Given our discussion re Greenwater recently, some of you might be
interested
> in the following information that I will be posting to my web page
shortly:
>
> Phytoplankton ~ Greenwater:
>