Light & Height

["Jim Leonard" <jdl at voyager_net>]

Do the height of the lights form the water in a canopy have much effect on
light intensity through the water column?

 I have built an experimental hood to check design concepts for a larger
project in the future.  I have mounted 2, 24" shop lights at the top of the
hood.  The bulbs are: 2. GE Sunshine Full Spectrum 5000 K,  1 GE Plant &
Aquarium,  1 Sylvania Gro-Lux/Aquarium, all  at 20 watts.  All this is
mounted so the bulbs are 7" above the water.   The hood is on a standard 29
gal. tank.  This arrangement seems to work well for tank access.  At this
time the tank has no glass canopy but may in the future.  Any comments
appreciated.

Jim Leonard
Ohio