My panda cories have always been a little shy and hide under their rock/in the plants with the occasional playing in the front of the tank (pretty darn adorable). Just recently, I got a new hood (no lighting changes) which enabled me to put my fry refugium in the back of the tank. In the process, I moved my filtration and heating to the very right of the back side of the tank. Ever since I did that, the cories have been eagerly swimming up in the current of the filter by the glass near the top and then swimming back down. They repeat this over and over again. It looks like their just kind of having fun and following each other around. Has anybody had anything like this happen before? Is it normal of them? All of my params are normal and I haven't changed anything besides what I already said. Thanks for your input!