I am in the process of moving all my fish from my 150 G to my 500 G. A month ago I moved my 3 Balas to the new tank. Everything was fine in the old tank. Last weekend I moved my 3 Tin Foil Barbs into the new tank. My 10 Clown Loaches that remain in the old 150 are not pleased at all at this. It seems that they feel less secure with all the mid level fish gone in the old 150. My loaches are so skittish right now. I have never seen them move so fast before. They go crashing into the side of the tank when I approach it. I had hoped that they would have settled down by now, but no luck. If the water paramaters are good in the 500, I may move the loaches over this weekend in the hopes that they will find comfort and settle down.