new 30g ready to go just need ur advice

[pledge]

So i have a 30g tank and its all set up and been running for weeks. I was curious what type of aggressive fish i should get. I would like a needle nose gar but from what I have read they get big and a 30g isn't all that big for that guy if he gets bigger. any advice on what type of fish i can get? oh and also if i get aggressive fish what other types of fish can i put in with it.. I know just other aggressive fish but could i put like an oscar in with a n.n.gar? just as long as when i get them they are about the same size?
Thanks a lot for your help too

 

[SkiPro]

well i wouldn't put a gar or an oscar in a 30 gallon. you said your tank has been running a few weeks, what is in the tank right now??

 

[pledge]

oh i just have some small little zebra danio.. this guy at the local aquarium store told me to throw them in my tank to make sure everything is running right and if they survive then my tanks in good shape with all the chemicals and what not.