While I doubt I will ever get so big as to afford the expense of a cooling system as described by the following link, I thought it may be useful information to those who are planning large scale Commercial Aquaponic businesses.
I love the info available from the University of Florida.
Fan and Pad Greenhouse Evaporative Cooling Systems
I agree that they put out some really good info. Take a look at the link below for yet another one of their systems, specificly designed for Aquaculture. Since the air & water are cooled during the process of evaporative cooling, it makes a great way to cool your fish tanks on really hot days.