honestly, people just tell you this because feeders from anywhere have been exposed to everything. I dont know much but I do know if you love your oscars you dont want to intentionally give them internal parasites. Oh yeah , also, feeders are not enough for any fish (nutritionally). They will need alot of variety, when small oscars will accept flakes and small cichlid pellets (and small fish, ect. BABY FOODS!!!) when larger they will eat anything, algae wafers, krill, baby shrimp, crab, brine shrimp, live, frozen, freaze dried anything,, shrimp pellets, Flakes with spirulina...
Somewhere on this site you can find out better nutrional info for your fish, Im just here to say feeders are not enough,,,
But if you do want to feed live fish every so often,
Go to your lfs, and find the best, healthiest looking livebearers/guppies, mollies, platies, endlers or swordtails, theres more but they are not that common.
put them in there very own (cycled) tank, or use the oscars water and filter media mixed with new treated water.
buy 10 female and 2 males= alot of babies- if the parent fish survive, it took me alot to get any to survive from the place I got mine from.
Watch these fish for weeks, some will die, you MIGHT have to medicate these new fish.
when you are positive there are no signs of flashing, fin rot, gasping ect. then begin feeding the grown out fry to your fish.
to help you along ,, you will need a fry grow out tank( 5.5gallon will do)with a sponge filter or something similar,, or the parent fish will eat there fry faster than your oscar ever could.
buy alot of FAKE plants and just float them in the water, check the plants every day for baby fish. have lots of plants on the bottom to and going from top to bottom.
fry also hide in the gravel, look closely,, this is annoying , I know but is sooo neccessary to keep your fishies safe,
also , when you get the livebearers, the females will be having fry from the pet store males
every 2-3 weeks five or six times. So quarintine these babies to... or you could just buy those poor feeders who have anchor worm and tb. and try to treat them but this is just not good enough for me.. It takes a long time before you get the results of all this but I say its worth it for my little guys, besides I like livebearers to
sorry bout the long boring posts,, just trying to help!!!