Koralia Evolution is a new power head from Hydor. I have recently purchaced the 550GPM model for my 90 gallon. I wanted to try it out and see if it is powerful as they say. It moves water around in my 90 gallon tank very well. The box rates it for a 50 to 70 gallon. But you can size your power head to what ever you want to to suit your needs. It is a very quiet power head, my filter makes more noise. It has magnetic suction cups for easy and secure mounting in your tank. It is a very strong magnet so be careful with it. It also can be adjusted to any direction. This power head can be used with wave controlers and timers. They do have there own controler or you can use any controlers, from what they advertise. I am very satisfied with this power head. The price for the 550GPM model was $39 from my LFS.