Numpty UV question

[millsn]

I'm sure this is a daft one but..Should I let my new tank run up for a while before using a UV steriliser? My rationale is thatif the steriliser does kill off bacteria surely it also kills off the good stuff that presumably meanders around the tank when it's not in the filter? Could someone please enlighten me?

[chefkeith]

A UV sterilizer won't eradicate bacteria, fungi, algae, or parasites. It will only slow down their reproduction and limit their populations in the water column. The only things potentially affected are those that travel through the UV chamber. In theory, a UV sterilizer might slow down the nitrogen cycle process, but in theory, it may also speed it up because more oxygen and carbon should be available.

[millsn]

Interesting. Thanks chefkeith, I had thought it was an eradicating measure.

[OneWay]

It does work great to help remove ich from the tank

[andyroo]

I was under the impression that nitrogen-cycle bacterial required a substrate such that a UV filter didn't affect them in an established system? Such substrate can be stone or gravel or plants or sand or filter-media, but can also be junk and organic flotsam in the water that will be (yes) meandering/bobbing around and in doing so spreading the bacteria about... including through the filters. I'd probably err on the side of caution and let the tank get going before you switch the UV system on. Fish (well, at least the higher-$ ones) shouldn't be in there yet anyways.