In continuation to my last post, as I explained I'd like to conduct various behavioral experiements on crabs and at a later stage incorporate an Octopus into the "games". My crabs, like many octopus, are nocturnal. So most of their movements and activity are at night. I figured mabye here some one will have a good idea to a little problem i have. I'd like to switch the crabs to a day/night schedule were the day is night and night is day. (So i can work on them during "my day"). So i'd have the normal lights go one say from 8 pm to 8 am and during my day-their night, have on some sort of light that would "abide" by the folowing rules: 1. minimal light to the crabs so that it will be as close to "real" night as possible. 2. enought light for me to see them and most important- record their movements with several video cameras (some analoge, some digital) and a normal digital camera. i have read that invertebrates barely see in the red spectrum. i.e.- above 600 nm or so. I tried normal light bulbs painted red (for photography dark rooms) but there wasnt enough light to film them and see all the little movements. Some one suggested using red led lights and mabye even sealing them in plastic tubes and putting them im the water.... any ideas? I saw a few "red" pictures on this site so i assumed this is also a "common" issue amongst cephalopod keepers. Any ideas in how to make such a setup will be greatly appreciated!