Aquarium Sterilizers

[crackmonkey]

Do sterilizers have two pipes like an external filter? I want one but I have a Juwel tank with an external filter taking up the lefthand side gap and the internal juwel filter in the way of the other. Or can you get internal ones?

Do you have to clean them or add media?

They kill harmful bacteria but how don't they kill beneficial bacteria?

Which one is the best?

 

[kevinf]

Do sterilizers have two pipes like an external filter? I want one but I have a Juwel tank with an external filter taking up the lefthand side gap and the internal juwel filter in the way of the other. Or can you get internal ones?

Do you have to clean them or add media?

They kill harmful bacteria but how don't they kill beneficial bacteria?

Which one is the best?

I am a novice at aquariums, but I am a microbiologist and a UV steralizer must kill most bacteria that travel thru it including the good ones. I suspect that the logic behind the steralizers is that the "good" bacteria live mainly on solid surfaces like the filter, substrate, glass, plants, and decorations.
cheers

 

[Lateral Line]

You are correct. The UV kills what passes through it. Most of your beneficial bacteria, and indeed, a lot of bad bacteria, blue-greens etc., are sessile and do not pass through the unit.

UV units are pretty much useless in a freshwater tank.