fin nipping

[rookie]

i recentlly had two barbs die i beleve to nitrate levels since then i have done alot of research and found that was the problem. however when the two died i was left with only 3 barbs. i feel that the smallest barb was being singled out by the other barbs and the angel fish and they were nipping his back fin. in attempt to help the little guy out i got 3 more barbs today for a total of 6 tiger barbs and 1 angel fish. i hope that more in the school will help him, but is there anything else i can be doing to help him.

[Red]

Watch for infection of the tail, you do know your 10gal is way overstocked?

[rookie]

yes i learned the barbs need more room to swim and the angel needs a taller tank but im hoping that within the next week or two my cousin is giving me a 55 gallon. and the angel is still small. but how do i look for infection