ok so big 220 tank wit like a 7 inch aro and 2 like 2 or 3 inch oscars... i got some jack dempsys to kinda fill in the gaps and they were at least 3 when i got em. i let them chill in the bag and stuff for like a hour then dropped em in.... woke up[ the next morning and my oscars are no where in sight, so i start tipping over all the decorations and stuff looking for them, i finaly find them hiding in the deco and all their fins are all torn up and their sides are like that white color like they been gettin beat up,,,, i ended up taking them back to the pet store cause the jds were extra the oscars were what im really wanting... they are makind a full recovery now but i just wondering why the jds wwere attacking them when they have all that room, all those other spots to set up a teritory and yet they f with the others, i just dont get it. are they normaly that aggressive, is there a diff fish i could get to fill that gaps that wont almost kill my oscars.