The importance of White Balance in tank Photography
I have also found it a challenge to take pictures of the tank with all the multiple color spectrums that shine down on the tank. My small nikon camera is pretty powerful, but doesn't have any manual settings. Without setting the white balance you usually end up with a very blueish tint to all the pictures. To set white balance you first need a camera that allows you to manual set white balance. Basically you put something white in your tank like pvc pipe or a plastic lid and then set your white balance on that under your lights.
I took the advice from Malev's Reef site. Here http://www.melevsreef.com/fotos.html