aquarium photography

a friend of mine would like some shots of his aquarium. what would be the best way of doing this in terms of eliminating reflections?
took some close up of some of the fish but could not get away without reflections when trying to get the whole tank
any help much appreciated

lift the top off, shoot your flash from above. (one on each side of the tank aimed down at 45 degs works well.)
then if needed hang a black sheet/curtian in front of the aquarium, and cut a hole and shoot through it.
lastly... many fish will chase a laser if you need to get them to pose in front of your lens...

Do try not to drop the flash unit in the water though!