I have a 70 gallon aquarium right now that I would like to turn into a piranha tank or more specifically a rhom tank. But I can only afford a smaller rhom and I have heard that they are very shy sometimes and so I was thinking maybe I could put some tetras in there or other fast fish to maybe make them piranha feel more relaxed. I realize that to a smaller rhom a tetra would be a worthwhile meal so I was thinking that maybe along with the tetras I could put guppys or mollies in. Since they are slower, they would be attacked by piranhas and the tetras would be spared. And the mollies/guppies would keep reproducing at the same time. Could this possibly work or will the rhom just kill everything in the tank? I would be sure and put lots of plants and hiding spots in too.