New Fish Question..

[muffin]

Hey guys,
I went to the LFS the other day to add some color to my 10 gal tank. I already had a female molly in the tank and have her fry in a breading net also in the tank (they are growing nicely). Anyways, I wanted to get a couple 'peaceful' fish to add to the tank. I ended up getting a male white cloud and a male cherry barb. From everything that I have read, these fish are peaceful. I also understand that I should have gotten a school of these but that's a different topic at a different time.
Now to the question. My cherry barb hides in the back and gets picked on by the other two fish during the day and when I have the direct light on. The second I dim the light everything changes, as in it's payback time. The cherry comes out with fins all fanned out. The White cloud also fans out his fins.. but now the cherry will chase the cloud around the tank. It's kind ofexciting to see. Also, if the molly gets involved the cherry will chase it away.
Is there anything that I need to be worried about? Is there something about chery barbs and lighting that makes him all of a sudded become aggressive?
Any help would be greatly appreciated.

[kimmers318]

That's a new one....different personality traits depending on the light. Maybe the cherry is actually a big sissy and only feels big and bad when he thinks no one can see him:14: . Seriously though....although few have actually seen "mean streaks" come out at night, I have heard of several people who find suspicious fight damage the morning after when having added new fish. If it doesn't look like they are doing any real damage all might be okay eventually, but with schooling fish you generally have better behavior when they have their groups so it may turn into a neverending battle in the tank which will ultimately stress your fish and leave them vulnerable to disease and infection. If it doesn't settle down I would suggest you take someone back to the store and try for a school of fish or different species.

[muffin]

Thanks. I watched them a little longer tonight. after about 20 mins, the barb went back into the corner behind the plant and hung out. I just thought it was weird because this was the 2nd night in a row that when I changed the lighting seconds later I had action. I will keep an eye out and see what happens. Once again thanks.

[cocoa_pleco]

My krib used to get pushy with all his tankmates, but after 2 weeks its just MEH and he will peck if a fish accidentaly knocks into him.

Give your fish a little time

[Abbeys_Mom]

Barbs are notorious for being nippy. If you start having torn fins on your fish, I would take the barb back and get more minnows.

[cocoa_pleco]

yeah. If there is physical damage, take em back