I have a P. Electra in a quarantine tank with some sand. When i changed the water a few days ago and then again today when I was filling water test vials, this fish dove under the sand. I carefully dug it out, and it immediately did it again. The fish did not appear sick, it was in quarantine to regrow some fin damage. It looks pretty rough now, because i think it injured itself today. This was a first for me.