>Dear RML,
>
>Is there any adverse effect of fish never experiencing the dark?
>
>Do fish need sleep?
>If so can they get it when there is always a light on?
I've seen some good answers already Matthew, but I'll put my 2 cents worth
in too.
Probably the key thing to remember with tanks always, is that the fish are
confined to that one very small environment, where they can't swim off to a
better bit of stream if conditions don't suit them.
Out in the wild they experience full moon nights lit up like daylight, and
other nights with cloud and no moon. But even on the full moons they can
still move about the stream and find a bit of cover under a log , or under
an undercut bank where they can get a good snooze.
Maybe you might have to consider putting some large plants, rocks or wood in
the tank, strategically placed to provide an area of heavy shadow from the
security lights. Painting the ends and back, (Externally) if there is
nothing there at present may help too.
Good luck
Doug Collom