Am I overstocked?

Yeah most chains have a policy against returns like Petsupermarket they will sell you a ton of fish at reasonable prices on certain species but once bought they will not allow the fish back in their tanks plus they own grow out ponds in Florida..
 
Seems like the black oscar wants to be the ONLY oscar in the 125 gallon tank (though he's somewhat ignoring the silver dollars. the silver dollars group together tightly whenever it seems like he wants to attack them).

the black oscar keeps chasing the albino wherever he/she hides. i mean, the albino is already hiding but the black oscar actively seeks it out to try to bite it.

EDIT: black oscar is trying to nibble the silver dollars. he sneaks up behind them and goes for a bite (and misses)

Sorry to say but that sounds to me like the Black will not co-exist with the albino - try your best to rehome. Thing about fish, and cichlids in particular, is that they choose who they will live with.
 
your not overstocked, but once those things grow you will be close =) i'd let them grow and once they do move 1 or 2 to a different tank
 
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