Kiwi Fish Kid

I have 4 golden barbs, 4 ruby barbs, 2 oddessey Barbs, 3 Tiger Barbs and 3 Green Tiger Barbs which have lived happily together for the last 2 years.

Suddenly they have started nipping each others tails! It seems to be the Green Tiger Barbs vs the Tiger Barbs (none of the other fish are being attacked and are quite peaceful). I was told to keep Tiger barbs in groups of 6 and that 3 of each would be OK.

Why have they turned on each other after having no trouble for the first 2 years? I put the 3 Green Tiger barbs in the isolation tank, and the main tank with the Tiger Barbs settled down.

Once the Green Tiger Barbs tails grew back, I put them back in the main tank, and again they began nipping each other.

Any ideas on why this has happened and do you think they will all live happily together again?

Butterfly

Have you changed anything in the tank? added anything? Tank maintenance change? Sorry for the questions , they will help us figure out whats going on. Welcome to fishLore!
Carol

Barbrella

I think it might be stress from the overcrowding, since this tank is only 20 gals (80L)

Tiger Barbs need lots of room.

TheJimsterness

they seem to be overcrowded. Tiger Barbs nip when they're stressed out. Also, they seem to be getting old, i don't know if they get mean and ornery.

TheJimsterness

oh yeah and the tigers aren't racist, they treat green and regular tigers the same

snowball

well they always said to be as specific as you can.