What can I do to stop my fish from biting the others?

Barbs are best kept in schools of at least 6 as well. The thing you need to know about most barbs is that most of them are bad fin nippers, and should not be kept with fancy finned fish. I would honestly recommend returning the 2 barbs and getting some other tetras in their place. But you have to remember all of these are schooling fish and are happiest kept in groups of 6 or more.

Okay, seriously that guy who you talked to doesn't know what he's talking about. Barbs CANNOT go with neons or guppies, that is one of the WORST combinations of fish. Take them back to the shop. Barbs are notorious fin-nippers. Second of all, (and it's not your fault, you were just misinformed) barbs should never be bought in groups of 2. 4 minimum, but six is better. This makes them less aggressive, and it keeps the aggression within the species (and it is normal for barbs to be aggressive with each other.) (But still, no matter how many barbs you buy, they cannot go with the two most sensitive and least aggressive tropical fish, neon tetras and guppies.) Take the barbs back to the store, and buy some Serpae tetras instead, or other gentle tetras (e.g., don't buy black tetras, etc.) You need at least 3, because they are schooling fish. They are very gentle.

Best of luck!!

p.s. Platies and mollies work well too with neons and guppies. They prefer a tiny bit of aquarium salt, though.

Barbs are notorious fin nippers. They are difficult to mix in with other fish, especially community fish such as Guppies and Neon's.

I would advise you to take them back to the shop or to give them to someone who has a tank of barbs as it is unlikely that the fin nipping is going to stop and it will only stress out your other fish.

most pet shop keeper only want to make a sale so they dont tell u the pro`s or con`s on fish unless they really want to 1 barb is ok but not a pair also for guppies the colourful tails will attract the barbs and this will become to fighting within the tank either keep 1 or get rid of them both good luck

Many pet stores goal is to sell things, and many will say most anything to make a sale. Gold barbs are notorious nippers and they do best when kept in a school of 5 or more and they may bicker among the school about the pecking order. Avoid keeping them with long finned fishes. Get 3 or 4 more and see if that helps. EDIT: Given their generally peaceful nature, they can live with most other fish.....when kept in groups....

I always had problems with barbs. Just give them back to the pet store and tell them to give you store credit to get some more neons or something that will get along with your fish.

If you ask someone that has fish to sell if they will get along,the answer is always "yes".

Your tank may not be overcrowded,but it could still be too small for the population of fish you have chosen. My point is that the minimum amount of water required for a fish to survive in may well be different than the size of the tank required for fish to interact in.

You could keep any number of male Bettas in a tank if there was enough space for the less dominant animals to escape to.

You could try giving him a good talking to, if that doesn't work make a rule of no more food until he behaves himself. If neither of these suggestions work eat him for dinner with some salad.