Hi guys 1 mounth or so ago i jioned this site b/c i had bought two rather big oscars and was in serious need of info. I traded those guys in in favour of four baby oscars and there doing good exp for one which might have hole in the head:( I was wondering i know that your not supposed to be able to tell the diff between male and female but i have noticed that two of the three of them have a more round bottom section towards the tail well one was falt does this mean anything?

Thanks:)

55gallon tank
4 lava rocks
2 aqua clear 50 filters
aqua clear 30 power head with filter dub
2 plecos
1 coulmbian shark
3 oscars

I know of solid way of sexing your oscars other than actually witnessing them spawn. That probably isn't going to happen in that small and that heavily stocked of an aquarium. I've kept that many fish in a 55gal before and it's basically impossible to keep the water from turning into fertilizer. I'd say you've got 8-12 months to save up for at least a 125gal setup.

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Unfortunatily i cant get another tank due to my house being small lol. I only plan on keeping the 2 plecos and 2 oscars any ideas on how i could make this work?

I dont care how much work it is lol?

Any help would be appreciated:)

An Oscar can get HUGE. Some 18 inches, any healthy Oscar will reach 12 inches. The shortest interior dimension of a standard 55gal is 11.5 inches. You can't get around that issue. You could be pushing 800 GPH through biological filtration and with enough water changes (Maybe twice a week)and very careful substrate cleaning there is the slightest glimmering chance that your water will be stable, if you basically starved your fish. Problem is, even if you're a genius with water chemistry, your fish WILL physically outgrow that aquarium. Trust me, I've kept fish all my life. I've learned that lesson the hard way. If your space is too small for a 125gal start looking for a 90gal. It's the exact same length, only deeper and taller.

THX for the info how do you caculate the filtration rate though?

Here's an old shot of my 55 back in the day. It looks crowded because it was. That Oscar had about a half in of turning space. Notice the filter intake that's broken off in the upper right. That happened twice day. Too big of fish in too small an aquarium!

Mneillssen has a point. Your tank needs to enable your fish to turn round


The rule i think should apply is that if your ammonia or nitrite go above 0 (without a good reason) you need more filtration. If your nitrate go above 40ish then you need either to get rid of some fish or do more water changes.