About 2 weeks ago, I bought 17 Pristella Tetra. I also bought 3 Alestes Tetra that were kept in the same tank as them. I added them to my 55 gallon which consists of a few other fish, not many and nothing very big (my list is on my profile, Tank #2). The only time I see these fish is at feeding time. The rest of the time they hide behind plants. I'm frustrated because I thought they would be a beautiful school of fish to watch in this very bare tank.