UV sterilizer for small tank options

[Zorix]

Hi again everyone.  You all have been extremely helpful to me recently and I have greatly appreciated it.  I am having another issue that has started to happen since about last week.  I noticed small creatures jumping around in my 2.5 gallon ramshorn snail tank, at first I wasn't sure what they were but I did some research and they look to be copepods.  I am concerned because I plan to transfer some snails out of this tank into another and I don't want to transfer the copepods with them.  I read that doing frequent water changes can help, which I have been doing for about a week now.  About 50% water changes every day and it doesn't seem to control them.  Starting to see a few of them getting larger and definitely see the copepod features clearly now.  I read on another forum that a UV-C sterilizer could be used,   I like this idea but since I'm dealing with such a small tank, the options I see are for very large systems it seems.  Does anyone have any recommendation for an external system with small diameter hoses?  I figure I can probably pump water through it temporarily for a while until they disappear.  Thanks everyone!

[Daniel]

Many forum members consider copepods highly desirable members of an aquatic ecosystem. But if I wanted to rid my aquarium of copepods, I would use a small hungry predator like a guppy or really just about any small fish.

A UV sterilizer could conceivably work in the long run, but it might be a very long run. UV work by disrupting the DNA of any life that flows in front of the light. Many of the copepods in your aquarium (even small ones) potentially might never go through the sterilizer. The disruption of the DNA interferes with reproduction but doesn't actually kill the microscopic life in your aquarium.

So a small predator would be a cheap and quick way to rid you tank of copepods.

[Zorix]

Interesting.  I had not considered keeping a guppy or just leaving them.  Thanks!