The shop had this lighting set up on a aquarium and was very surprised after some of the comments i have heard from other hobbyists. The set up consisted of the duo combo that has a marine white light strip and a marine blue strip. These represent better value as they are cheaper purchased together but WOW! the blue is megga powerful and would have to say that if using this lighting your gonna need two whites to one blue as a rough guide, although it is not the cheapest way to light your tank. Considering replacement bulbs with T5's and metal halide lighting and the massive reduced energy consumption the seem really efficient. The other great thing is the reduced heat, you can touch the light unit and not get burnt. This also makes you realize how much less evaporation so energy savings all round.
Using 4 T5's, i use about 6 to 7 litres of RO for evaporation every week each bulb uses 24 watts of power with T5's. Even if i used three white and one blue Aqua rays rated at 12 watts each this amounts to 48 watts as apposed to 96 watts that is a saving of 50% on lighting and not to forget about £80 in bulbs every six to nine months. I think 4 aqua rays may be more than required.