Actually, my Reds are the sweetest fish in the tank! I know, weird huh? I know they are suppose to be very aggressive, but mine are not. It was my Yellow Lab who was the meanest fish and my Acei fighting so badly. The Reds and Labs were spawning all the time, (I didn't have an Acei male yet) but they just hardly had room to move any more, especially the Acei. I got myself a cheap 55 gallon acrylic tank off Craigslist and used that until I could get a nice glass setup. It was cool the first night after I moved them. The Acei would stop short at the 36" mark like there was still glass there. When they realized it was longer they spent the next 4 hours zooming from one end to the other LOL. It is also nice because I have been able to also add a small group of Greshakei now too.
I ended up having to add bigger rocks because they no longer fit in the caves the river rocks made. Then the rocks took up a lot of space, added to that they got so big and were stacked on top of each other. I have more fish and they are just as crowded now in the 55, but there is more "running" room now. I think I would have been OK if they all stayed at 4", but they got huge on me! Like I said, my adults are now 6".