I've seen oscars kept in a lot worse. 10 gallon tanks and such!!! Though this tnk will be a bit cramped when the oscar reaches full size, it's not entirely horrible considering where many of them go. Most peopel think 10 and 20 gallon tanks are perfectly fine
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But idk, maybe I'm to liberal and forgiving when it comes ot fishkeeping
How can it be fine when the fish is bigger than the tank itself?
The fish isn't bigger than the fish! An oscar grows to an average of 12" in home aquaria, given if in better conditions will reach greater sizes. 40x12x18 (LxWxH) just is a bit cramped. The size you should have for tank demensions are a minimum of 4.5x the length of the fish, 1.5 times the length in the height and the width. In other terms, the tank should be a minimum of 48x18x18 like suggested. But the measurements are 8x6x0 inches off. To me, that isn't so bad compared ot what many of them are kept in. All I'm saying is that it can be a million times worse and instead f people seeing this, they always jsut see hte bad in things, not the good. The oscar can be in a much smaller tank, but it is in the tank that size (40x12x18). Nowhere in the original post was the size of the oscar mentioned. I'm assuming it is probably middle sized (4-8" or so). So really it isn't all that bad as it can be worse. But that is jsut my opinion. I try to look at things in a positive light. The oscar can be in far worse conditions than the ones it is currently in right now. That's all!