HELP!! I have 10 neon tetras in a 10G. One is BULLYING every other fish.

[nellafantasia]

I have a relatively newly cycled 10G tank with plants. (Parameters have been stable and today there is 0 ammonia, 0 nitrites, less than 20ppm nitrates and pH of 7.5.) The color of all fish is good though some are brighter than others.

There is one neon who, when he is not hiding out in the fronds of a java fern in a spot he has commandeered, is fighting every other fish. He darts at and chases them. Or if one fights back he goes nose to nose in a whirl sometimes all the way to the water surface. He picks on them all but I think especially the smaller fish.

I do have some floating pennywort, hornwort and watersprite, though not a whole lot. I have been waiting for my plants through the mail since I have NO other fish stores within a 90 minute drive other than Pet Supply Plus.

Shall I just euthanize the one trouble maker or what? Thank you in advance for any suggestions.

 

[nellafantasia]

My 10 neon tetras have stopped fighting. Everyone is peacefully swimming around. The one fish (looks like it is a female) continues to hide out in her favorite spot in the center of the tank in the middle of some java fern. She (?) still chases out anyone else who swims in that spot.

Is it possible that the original 6 neons and the newly added 4 neons had to set a new pecking order? Water parameters are stable with no ammonia or nitrite.

 

[ustabefast]

Hopefully the troublemaker settles down now that a pecking order is established.
I once had a hyper aggressive male endlers liverbearer who terrorized every other male endler in the tank.
He never behaved and I had to rehome him.

 

[nellafantasia]

Hopefully the troublemaker settles down now that a pecking order is established.
I once had a hyper aggressive male endlers liverbearer who terrorized every other male endler in the tank.
He never behaved and I had to rehome him.

Thank you for your response. After 24 hours the fighting stopped. I hope it stays that way.