When I first got my elongatus, he roamed the tank but soon settled to under the piece of driftwood as his hang out and would only be found swimming when the lights when out. I had tried wrapping the light with electrical tape and put colored cellophane under it to try to dim it and see if that would work thinking maybe the lights were too bright. That didn't seem to work so much. So I switched to a actinic bulb to see how that would fair. I liked the look of the tank but same result, he would hide until the lights went out. So after awhile I decided to switch the 48" light to a 24" light on one half of the tank. The piranha responded greatly to this. I know can see him swimming all over the tank even when the light is on. Just thought I'd share this for anyone who might be experiencing the same issue. Try playing with the lighting and there may be some success.
