Did you edit any of these photos in photoshop?
Monster fish keepers have a photography section that has a good level of advice on lighting etc.
Looking at the pics i would say that the level of flash is too high illuminating the whole tank rather than just the fish
Steve
the trouble with the speedlite ive got is its power isnt adjustable , so its all or nothing , plus its not compatible with high speed sync on the wirlesss trigger ,therefdore restricting me to shutter speeds of 1/50th and lower , which then has a knock on effect that i cant use as wide a aperture as id like or the shots are blown out . id like a 430exII but cant afford 1 at the moment so im having to experement a bit and adapt things to suit. not perfect yet but getting there . i darkened the background in picassa on the 4th and 5th pics as id not long fed them and the flash shew up every tiny little particle in the water
none of the colours etc have been tampered with in any way tho ( im not that clever lol)