my recently purchased trio of mono's have turned out to be killers. at first they would harass my oscars (oscars a good 1-2in larger then my mono's). the mono's would chase the oscars around the tank, but never really cause them any real damage. today i found one of my oscars dead and the other beaten up pretty bad. didn't think mono's were that agressive, does anybody else have mono's that are this aggresive?