The A80 has an awesome array of features including several different White balance options. I've finally been able to filter out a lot of the artificial yellow/green/pink haze of the aquarium lights using this...
I've even been able to use a flash finally for in-tank macro shots and not have the colour look totally yellow and washed out.
Easiest way to set your White balnace is to keep a small white piece of plastic at the back of the tank, something around 3" x 3". Focus on it then do an automatic White balance adjustment.
In my two largest tanks I don't do this as I have white sand in the bottom I use for this purpose, but the same priciple applies...