When I introduce new fish to an established aquarium it will usually be in the afternoon. I feed every morning, so the tank would be fed as usual the following morning. For those tanks that also get occasional evening feedings, I would not do so the day of new fish, but wait for the next.
I have never bothered over lights; tanks are heavily planted (security for new fish if needed), lights are on timers and it is too much fuss to mess with them. When possible, I would introduce new fish well before the lights go out, 3 or more hours, so they have some chance of assessing the environment and tankmates before darkness. Except for some catfish, fish are inactive in total darkness.
Last edited by Byron; 01-17-2010 at 04:29 PM..