Re: [RML] Melanotaenia trifasciata

Bruce Hansen (bruceh at
Fri, 13 Aug 1999 10:49:56 +1000

G'day Peter

> Give them water, heat it to about 26oC (80oF), keep your water clean and
> will do fine.

At least for a short time but they may not look their best.

> For most Australian species specific water conditions are not
> critical as over the course of a year conditions at any given location can
> change radically from very soft and acidic (from tanins, not fish poo) to
> harder and alkaline.

I'm not aware of any surveys of Cape York streams in the wet season that
confirm that they change from soft and acid to become hard and alkaline with
the addition of lots of rainwater (which is usually slightly acid and soft).
So my prediction is that they change from soft and very acid to soft and
less acid.

Of all the Trifasciatas that I have collected and kept over the years
Michael, only Goyders seem to need pH over 7. The natural waters are around
200 ppm hardness there and that is the only place i have found Tris in hard
alkaline water.

I agree with Peter that fish are generally not as fussy about water
parameters as they are about water quality and tris need well conditioned
well oxygenated water low in nitrogenous wastes. I have also found that 80F
is the upper limit of their temperature preferences and they will happily
enjoy and breed at 75 and lower. I have caught 5mm fry in the Goyder River
in winter up there at water temperatures of 18C.

Even in hard water adding tannins will often improve colours, as will adding
CO2. But is hard to beat the natural stimuli of plenty of vegetable matter
and live foods plus water changes and current to make the males spar and
display and look their best. Remember dominance is a major factor in a
schooling fishes domain - so try to always ensure 2 or more males in your
schools. When Gunther Schmida "borrows" fish to photograph he always asks
for 2 males and a female. I believe that this is a major "secret" behind his
superb shots.

Lighting is important too - try to make sure the tubes are to the front of
the top of the tank and directed slightly backwards. You will be amazed at
the difference.


Bruce Hansen, A.N.G.F.A., Advancing Australian Aquatics.

Bruce Hansen, ANGFA, caring for our aquatic ecosystems.

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