Bad mix?

[Teknagen]

Ok when I first started my tank 4 months ago I bought a clownfish.. but I'm not sure if its true or false percula the display wasn't labeled. He seemed lonely so I recently bought another clown from same place.
When I got home the new clown is a totally different color and a little bigger.
They were doing OK for a week swimming next to each other.

Now the new one is kind of attacking the smaller one.
It looks like the smaller one having a hard time to swim sometimes.

Is this normal for one to attack another?

http://www.teknagen.com/tank/clown.jpg

[Slakker]

Yes, however, with your clown being alone for 4 months there's a possibility it has already turned female, and I would venture to guess that the new clown is also female.

If that's the case, they will fight until one or both of them is dead, so keep a close eye on them over the next few days. If it seems like the new one is actually hurting the smaller fish, I'd remove the new one, take it back to the store, and get one that is noticeably smaller than the one you already have.

HTH, and good luck!