Ok, I have had my oscars for about 4 weeks now. I started with 5 but am now down to 2, natural selection. the remaining 2 pretty much eliminated the weaker ones. Still, its a better number for a 85g tank. They are growing nicely from about 4cm to 6cm and are filling up to a nice healthy shape. I am currently feeding them only Hikari Cichlid Gold pellets plus some other general community pellets, flakes, and freeze dried Tubiflex worms. There are clown loaches and a Blue Acara also in the tank. I feel that this is not really a complete diet, though they seem to be doing well.
Any suggestions as to what else I should be feeding them?

And jusy a interesting observation. They (Tigers) vary from day to day from being very light in colour to nearly black other days. Could that be Diet, PH, health?

@ colour change, have you tested the water at both stages of colour change? It could be ammonia/nitrite spikes. fish often change colour, clowns also make drastic colour changes, is mood related.

@ diet. there are plenty of diet posts, a search will turn up loads, but as general diet you doing fine. worms and insects as long as now pesticides are used.

You are spot on there Marcus, I have also noted the Clown loaches change colour a lot as well. I have to admit to being a bit slack when it comes to checking water parametres. I kind of go with the theory of if it aint broke, dont fix it. If all looks healty, I rarely do the water tests, eccept for when first setting up a tank. I did check the water about a week ago however and all was good. 0 Nitrate,Nitrites and Amonia. The Ph was a bit acidic at about 6.5 which I have now stabalized at 7.

Kanga-Fish wrote:


Hmmmmm.

probe1957 wrote:

with Hmmmmmm probe means that's a bit odd.
A cycled tank should have a nitrate reading.
Nitrate at 0 will usually mean your filter is not cycled.
Did you cycle your tank before you put the fish in?
please read this: www.oscarfishlover.com/helpful-articles/cycling-an-aquarium
How long has the tank been running?

Altering your pH is not to be adviced.
A steady pH between 6-8 is fine, altering pH is risky and can easily lead to trouble.

As you say natural selection, do you mean the oscars simply killed eachother and you let them, or did they just die like that?

ammonia, nitrite and nitrate of zero points to something wrong. did you test with strips or bottle types? If you used bottle types did you follow the instructions exactly?

OOPS...I caused some confusion. My water test kit does not contain a Nitrate test, will have to obtain one. The ammonia and Nitrite both gave Zero reads (Bottle types).
The tank has been running for 3-4 years as a community tank. Most of the inhabitants I removed before adding the Oscars.
As for the perished, two fell victim to a largish salmon tail cat who has since been removed. They were the harassed somewhat beforehand by the two remaining oscars and weren't in great shape. One other, an Albino did fall victim to the Oscars. I didnt realise they could be so aggressive to each other at such a juvenile stage. Its been clear right from the beginning that two of the oscars (Rio and Lima) were the dominate pair. They have thus far made no real attempts to harass the blue acara or clown loaches.

i feed mine krill, shrimp, worms, and crickets as treats along with hikari bio gold as a staple. Your remaing fish may have future aggresion issues along with water quality issues as the oscars grow because of the confines of an 85 gallon aquarium.