"K. Elliot" wrote in message
In order to increase my lighting I am looking to add two more 40W
flourescents to my canopy. Can I just buy a four foot shop light (at
Lowes or Home depot) and bolt it to the top of my canopy (as long as
there is glass/plexiglass between the light ficture and the water
surface)?

That's the jist of it...as an FYI, I've switched from PCF to T8s... cooler
ballast makes the temp thing a NON issue... If you used T12s, you could
mount your ballast outside the canopy, maybe in the cabinet...

or would this cause too much heat under the canopy or other problems
(the canopy itself has an open back).

see above...

Would I be better off buying a separate ballast and end caps and
hardware and remotely mounting the ballast? (I dont claim to be an
electrician, so I think this might be risky proposition.

got a friend who IS??? that's what worked for me.... I got the wood, the
ballast, tombstones, wire and took it to him when I had the canopy made, he
mounted the lights, ran the ballast outside the canopy...

Obviously, the reason for this DIY project is $$$ (light fixtures
specific to the aquarium hobby seem to so darn expensive).

You'll like the DIY route, because it's the way YOU want it....