It sounds to me like the fish are frightened. I have noticed this behaviour
in many rainbow species - especially in bare tanks/holding tanks. If they
are nervous or unsure they school up, lose their colour and sit towards the
bottom and rear of the tank.
If this is the case and you want these fish to colour up then you will just
need to go through the motions:
a. provide security if it does not already exist. ie., dark gravel, well
planted tank etc
b. provide good quality foods, preferably with a live component - but allow
the fish to fast at least once a week
c. provide good quality water - 30-50% water changes once a week. Generally
pH and hardness are not overly critical if you have reasonable water quality
out of the tap. (except in my experience for Goyder R trifasciata)
d. give them time to adjust to new conditions and yourself
I think that a light coming on when the room/tank is dark would be
sufficient to frighten these fish. Also with only 4 fish in the tank they
probably can't school much anyway. Excuse my Aussie ignorance but I don't
have any tables handy - how may litres is 20 gallons (most aussie aquarists
can probably relate to gallons but I am hopeless). It sounds medium to me -
is it about a 2foot tank.
Regards,
Baz.
-----Original Message-----
From: John Dowden <ejdowden at mindspring.com>
To: rainbowfish at pcug.org.au <rainbowfish at pcug.org.au>
Date: Saturday, 1 November 1997 4:15
Subject: [RML] Archer River Trifasciatas
>I have 4 Archer River Tris in a 20 gallon tank that seem to be behaving
>strangely. The light on the tank comes on for 6 hours at night and is off
>the rest of the day. During the day when the light is off, the tanks get
>some light from the room and the fish are very active. At night when the
>light comes on, the fish go the bottom of the tank and just hover in the
>back. The fish seem very heatthy and the water conditions are fine and I
do
>weekly water changes.
>
>Today I am off from work so I decided to turn the light on during the day
to
>see what would happen and they did the same thing as they do at night when
>the light is on.
>
>Do anyone have any idea what is up?
>
>John
>
>-------------------------------------------------------------------
>John Dowden
>ANGFA NA E-Mail: ejdowden at mindspring.com
>Rainbowfish Study Group Web Page: www.mindspring.com/~ejdowden
>-------------------------------------------------------------------
>