The more of them that you get, the more fun they'll be. I think they get to about 4 or 5" so you'll want to allow them room to grow, and I think your tank could hold 5 or maybe 6 of them.
I had 6 or 8 of them...the bigger ones killed the smaller ones. It was weird. I came out one more to see one finishing off the little one. All 3 smaller ones disappeared.
I had 6 or 8 of them...the bigger ones killed the smaller ones. It was weird. I came out one more to see one finishing off the little one. All 3 smaller ones disappeared.