Does it matter which is in or out?

[420benz]

Before i install this the wrong way does it matter.

 

[mrsclem]

If that's a UV unit then it doesn't matter.

 

[420benz]

Great Thanks

 

[Lisak1]

I would leave it out.

 

[420benz]

Why

 

[Stephen Noble]

Unless the manufacturer added some specific flow directional arrows, just mount it so that air doesn't get trapped (outlet higher than inlet) and in a manner that is easiest for you to replace the bulb.

 

[Lisak1]

I was being sarcastic - not a big fan of UV filters in the pond. Think of all the single celled organisms you are eliminating by using it. They make up a valuable part of your ecosystem.

But I should ask - what's your goal with the UV?