water flowing through uv filter wrong way

[marco]

I installed a uv filter 3 days ago.Last night i noticed the water was flowing through it in the wrong direction. Would this make a diferance? and why?
ps. I took it apart and made it right.

 

[mr . salty]

On Most UV's that I have seen it doesn't matter which direction the water flows.Just that there is no air trapped inside it.But as long as you fixed it,I can't immagin any harm could possibly have been done???