On my 20 I have a power filter and was running it on high to clear some junk. When I noticed that my rasbora were swimming into the current at the front of the tank. They were doing tail stands, head stands and rolls right before my eyes. They really seemed to be enjoying themselves. They even seem to wait in line to take their turn through the current. Really entertaining! I suggest it for anyone. You can really see the different personalities of each, One is the hog of the bunch, one is timid, another just keeps going after the others stop. Their colors are really vivid after their exercise. Thought ya'll might like to hear about it.
Take care...
Randy
Take care...
Randy