Possibly dumb question about Hydro Sponge

[The Zigman]

Ha, yeah there's a filter back there!
Need to thin out the vals soon!

Let me know if you need any more assistance.

 

[XanAvaloni]

Thanks Zig, those pix made it click and I understand the thing now. It's just like the sponge on the filter in my pond. Except that the current filter doesn't have a sponge, so of course it clogs up and reduces the waterfall to a trickle over the course of about a week. Now I know how/where to get sponges. Am all set.