UV Sterilizers question

[evenings]

We are thinking of purchasing one of these puppies and would like some feedback on this particular product.

http://www.captivereefs.com/images/es77070-1.jpg

Its a Coralife 9 watt turbo twist UV sterilizer for aquariums up to 75 gallons. They also have Coralife 18 watt turbo twist UV sterilizer for aquariums up to 125 gallons.

Is the Coralife 9 watt TTUV good enough for my 65 gallon tank?

[marcus russo]

never used one myself but coralife is a quality brand in their lights

[Atari]

I've never used one either but from what I've read you would be better going for the 18 for that size tank.

[ASpec]

One thing to keep in mind... UV's are rated for GPH as well as tank size. If you plan to put the UV in line with a pump make sure you're not pushing more that the UV's rated maximum GPH or you're effective kill rate won't make having a UV worth it.

[darb2]

I don't mean to be a pain, but why? What are the advantages and disadvantages of a uv unit?