Instantly improve the water circulation in your reef aquarium using a powerful Hydor Koralia Evolution powerhead! We are giving away a Koralia Evolution that pushes 850 gallons of water per hour through your aquascape using a mere 4.5 watts. Want better flow? ENTER NOW. Registration ENDS at 11:59 PM PST on 11/13/13. Details: Open to US residents 18 years or older. Void where prohibited or restriced by law. Winner will be contacted via email. Watch this video to see the Hydor Koralia in action!