Originally Posted by statenfish
this is his temporary home..he will be moved in to the 400 gallon when it is completed in a few weeks. there is a pleco wit him and and anither pacu added last week...the light is very dim and there are places to hide..the 400 hundred is basicaccy an exact replica of the pacu habitat so maybe after the move he will settle down a bit
That is music to my ears. I'm glad you have plans to provide what the fish requires, well done. In the interim, I suggest either leaving the light off (no plants presumably to worry about light for) or somehow reduce it and shade it as best you can.
A few weeks back I posted a couple photos of pacu in a floor-to-ceiling tank at the Vancouver Aquarium, it may interest you if you didn't see it previously, so I'm attaching it. The group of 4 (I think) pacu are in with two arapaima and a group of Leporinus. You can see how dim this tank is lit, notwithstanding my poor camera skills.