Whats the largest tiger barb you have seen? I have never seen 1 over about 3 inches, but the owner of a pet store I do business with informed me that they could get up to 12 inches in a large enough tank. I currently have 8 tiger barbs 4 in a 35 gal, and 4 in my 100 gal. IF I can catch the 4 that are in the 100 they are eventualy gonna go into either a 50 or a 55 with a pair of jack dimpseys. I had 8 in the 100 yesterday, but after an hour of chasing them with my nets 4 remain. I guess that I am gonna have to remove all decorations if I want to catch the remaining 4 Size of the tank that these go in is just gonna depend on which fits wehere my girlfriend wants to put it. Currently I have 2 50's that are empty, and am picking up a 55 later this week.
I've only seens them max out at around 4 inches. I think the pet store you go to misinformed you a little bit. granted, fish will grow beyond their average size in a healthy and spacious environment, but 12 inches seems a little overboard.
Thats kinda what I though. My girlfriend got the rest of mine caught, and put them in my 35 along with several of her gold fish last night. Still not sure where I am gonna go with these 8 barbs though. MY 1st choice at this point is a 50 with a pair of JD and a few bottom feeders. Other options are to leave them in the 35 that they are in now, or a 55 hex.