Silver Dislikes the Dark

[Beetlebug515]

Good evening all. So recently my wife and I have become concerned with some odd behavior from my 15" silver. For lack of better words, I think he may be afraid of the dark. He is currently in a 250, and every night I turn off his lights around 8 PM and leave a kitchen light on so he still has a bit of light in his tank. The idea being that he doesn't go straight from high lighting to total darkness. Even after stepping down his lighting gradually, after about ten minutes in the dark he will splash at the top of the tank a few times before settling down for the night usually throwing a bunch of water all over my kitchen floor. My main concern is that the tank he is in is a uniquarium. The filter is built on to the back of the tank, so the water level stays fairly high because of the design of the overflows. Its about half an inch from the top of the tank. Something I didn't really consider before restoring the tank for him. Have any of you guys seen this behavior? Is there any way I can minimize it? I don't want him to hurt himself, for anything around the tank. Thanks in advance.

 

[jwh]

I don't think it's afraid if the dark, for the first 30mins after lights out my tank is also very active before it settles down, I think the transition to dark unsettles fish, as in their natural environment unseen predators may come out and they need a little time to settle down. Both my aro and clown knife hit the surface, and at time have some grazes, never been serious though. My tank is open with eggcrate keeping the fish in.

 

[D-RIG]

My aro does the same thing when the lights go out ,
sometimes I'll hear a loud crash from the tank and
sometimes it's so loud I need to go out and make
sure everything is ok out there .