[CyberJester]

As far as sterilizers go. I like to keep one for when something does happen in the tank. I have a 3 watt (very small). Does not kill everything that goes through it, water would have to be moving very slowly for it to have enough contact time with the water to kill all the organisms in it.

I do not even use mine unless something happens in the tank. If a fish in my tank developes a desease. I remove the fish to quarintine then turn the sterilizer on for a week or two to prevent contamination of other livestock in the display tank. My sterilizer just sits inline of of my return pump. For the money when used in this fashion I believe they can be a real asset to prevent chain contamination of livestock.