Digital
Andy. Hi. New to the Marsh. Been shooting digital for several years professionally and here's two tips. White balance is a setting on some cameras that determines what is white and balances the other colors accordingly. This allows color corrections due to sunlight, flourescent or incandescent lightings. So if you tank pics have a green tint, try using all the possible white balance settings to find one that more closely matches what your tank really looks like. If your camera does not have a selection of white balance options, use your image software to adjust. Photoshop has some image adjustments features for correcting color. I have to use it to set thw white, black and gray blances to make difficult shots come out normal sometimes. Aquariums are some of the hardest to get right.
Your camera is obviously capturing the details (resolution etc) so it's just another step to overcome to get really fantastic results. Keep them pics coming.
Snailspace