year it should be fine i have 4 synos in my 500l and my fish still breed. you dont really have to mind the eggs too much as they will be in the females mouth!
i have 2 oscars and for the past couple of days they have been acting really weird they usually stay at the top but go down to the bottom and scare all the fish away from a couple of rocks. is this breeding behavior? how do you sex them? thanks