besides the obvious of it being Coralife making the turbo and Current making the Gamma, they simply operate a little differently. Coralifes spinning motion in the chamber vs gammas strait pass through is supposed to increase contact time to make them more efficient. Do more with less sort of thing. same basic principle though, get the water in contact with the UV bulb to kill contaminants. do read up on the use of UV thoroughly though to make sure you understand the positives and negativces of using them when you have a reef, many discourage the use of them in a reef tank with stonies like you want.
