Pre-Filter?

[Calikenny]

Ok, I got my pre-filter in place and it has junk on the surface of it. How do you get all that cleaned off without it spreading around my tank? I noticed I could siphon it off, somewhat. I was thinking I could just take it off and rinse it in a bucket of tank water. But that seems to not be ideal because it just goes everywhere once I remove it from the stem. Any ideas?

[Caliban07]

Maybe try siphoning it. Or turn filter off, remove sock and siphon the gunk that it releases at the same time then rinse.