It is highly advisable to keep in groups of 6 or more. They will be to busy seeking a "pecking" order to worry about other fish, generally. They will still be the fin-nippers of slow fish but it will be much better with at least 6. I had to learn the hard way. Dang pet store workers!
a friend a has 12 in his 50gal - and they run mob handed over the whole tank...
Its getting so bad that some of his other fish arnt eating.. he's looking at getting another tank for them...
they will take over a tank with slow peaceful tankmates. These are very high strung fish. My 7 do not have any problem bugging the other fish in my 35 gallon. I chose high energy fish that could keep up. At least by having them in a school of 7 they are not trying to chase other fish around.
I got rid of my tigers for just that reason They were entirely too nippy for the other fish, so I traded at the LFS. And even the workers told me at the LFS that the more you have will not make them leave the other fish alone.
My tank is much happier now. Now, if only I could get my rosy barbs to settle down..
They sure like to nip. I have a little TB, he is just under an inch and sometimes nips my sailfin pleco who is a good 8". The little bugger now gets charged by the pleco whenever he ventures too close, I think he has learnt his lesson.
Otherwise I love my tiger barbs, have a school of green, regular and albino.