UV Sterilizer Question

[guyerson]

Is a 25 watt Aqua UV Sterilizer too much for a 75 gallon tank? The specs say that it is rated for up to a 150g tank, but is there such thing as having too much wattage in a UV?? I'm new to UV sterilization, so any information you can offer would be greatly appreciated.
Thanks!

 

[scsinet]

No, it's not too much... it's certainly more than you'd need for a tank that size, but I've run a 25 watt on a 55 before.
Just be sure your flow is very slow... say, 125gph or less.

 

[footballhead]

Dont UV lights kill the good bacteria too? Just wondering.

 

[scsinet]

Yes they do... when the bacteria passes through them.
Herin lies the inherent limitations of UV units. They don't kill enough beneficial bacteria to hurt anything. The bacteria resides in the substrate, on the rocks, etc. A very negligible amount of bacteria is actually present "free" in the water column. ... and that's good.
At the same time, parasites, such as ich, etc, also are present mostly in the sandbed, which means that a UV unit can only have limited effectiveness against them also. .... and that's bad.

 

[guyerson]

Thanks so much for the advice!! Just didn't want to buy something that would do more harm than good if the wattage was too intense.