Juvenile Tiger Oscar & Red Tiger Oscar

[earthshaker]

Hello,

I purchased yesterday afternoon 6 pieces of 1 inch tiger oscar and 2 pieces of red tiger oscar, placed in a 20 gallon tank (with aerator for under gravel filter and an airstone)which I prepared 1 day before the purchase.

The next morning, the 6 tiger oscar were dead. What happened? Can someone please help me.

Thanks

[Eric]

You put 8 oscars in a 20 gallon tank ? Just confirming that I read that right! One oscar should not be put in a 20 gallon aquarium. These fish get very large and are quite aggressive. A min. aquarium of 75 gallons is needed for just a couple of these fish. I expect that your fish died from a ammonia/nitrite spike if you added 8 fish to a newly established aquarium at once. If you could give us your water parameters it'd be very helpful. I'd return the remaining oscars to the pet store and get something much better for your 20 gallon aquarium....

[earthshaker]

yup 8 oscars, but they were still 1 inch long and planing to transfer them to a 120 gallon tank after 2 months. I could not give you the water parameters because as of now there no available test kits for ammonia, nitrate and nitrite here. So do you think that its the ammonia nad stuff that killed my fish? I had no such problems when I started my 180 gallon tank (Eheim 2217 cxanister filter) with 1 golden arrowana. What suggestions can you give cause im planning to get my 120 gallon in a about a month or 2.

Thanks

[Eric]

Still 8 oscars is a bit for a 120 gallon aquarium, I wouldn't suggest it. I'd assume it was a ammonia/nitrite spike that killed your fish. Adding 8 fish to a newly established 20 gallon aquarium is sure to cause a ammonia/nitrite spike. I suggest that you do at least a 25% water change to keep the current fish in the aquarium stable. It takes A LOT more ammonia and more time to cause toxic levels in a 180 gallon aquarium. The bigger the aquarium the more ammonia has to be present for it to become toxic.

[oscarbartoni]

That is my thoughts exactly whereas you put 8 one onch oscars in a new 20 gallon tank that was not cycled the oscars threw of more ammonia than they could handle, that plus most people like to feed their fish the same day they get them which causes more ammonia, bad idea. In your 180 gallon tank the ammonia would not built up as fast and the bacteria would be able to grow fast enough to keep the ammonia from becoming toxic to your arrowana. The equatin I like to think of fo the stocking rate is the height (in inches) times the length (in inches) of adult size times the thickness (in inches) is the number of gallons of water that you need per fish, This does nottake into account the territoriol an aggressiveness of the fish.

[earthshaker]

Ok, thank you for your advice.