yes im new to oscars and have been reading alot lately. i have a 125 gallon with two emperor 400s and have 5 two inch oscars. im trying to find a pair and read on how to vent. my questoin is is venting a reliable way of telling between male and female O's and what is your opinion about it

Sure, venting can determine the sex of an Oscar, is it an easy procedure ? no way José. you cannot just do it by looking at the Oscars in the tank, I've tried it many a time when I actually know which is which and I cannot tell the difference between the two just by looking at their vents. I think it would be a case of removing them and using a magnifying glass.

the Oscars will have two holes right next to each other, one is the anus, the other is where their sexual organ is. this very basic diagram I have just knocked up will give you an idea. The female sexual organ is quite a bit bigger than the males, so her hole will be bigger than his.Having said this, when everything is tucked away the holes may not appear that different.

Personally, for the fish's sake, I wouldn't try to vent them unless it is absolutely necessary, Oscars do not like being removed from the tank and if you are not confident, you might end up dropping the fish

personally i would not bother with venting my oscars. if your setup properly just buy a few like you have and let them find their own mates. as long as you have a way to rehome the oscars that dont pair off this is the best way to do it.

on a side note 2 emperor 400 are not enough filtration on a 125 gal tank. while the o's are small you might get away with it but soon enough you'll find that they wont be able to keep up with the bio load produced by your fish. i would recommend supplementing with a good canister filter(a fluval or eheim) or adding a sump filter to your setup.

yeah i plan on adding a canister filter and thanks for the info ill let them do there thing

yer dont vent your oscers just leave them be until they r older

Your Oscars are far too small to establish their sex. Part of the fun in obtaining a pair is to watch the fish grow and interact with each other as they pair off. Much patience is required to breed Oscars a wait of approximately 12-15 months from 2 inches. I would not recommend removing any fish from the water just to find out what sex it is.