I don't mean to argue with you since your the guy on the sponge end of this conversation but I found with the tall sponges you have to soak them with water then hold by one end and swing/slap them against the side of the sink or bucket... a laundry sink helps here. Squeezing them got some gunk out but really didn't seem to get them clean for me.
Based on the colors in your photo they look like they have lots of embedded crud, mine looked like that and when I did the soak and swing routine there was gunk coming out of them for 10 minutes before I decided to swap them out for new ones. After new sponges my flow was restored, IMO it's worth a try, new sponges only set me back about $8 even at inflated Canadian prices.
Hey, it's not an argument
You make a good point - I'll elaborate on what I did - I had tank water I put the sponges in the water and squeezed them till they didn't give off any debris - which didn't take much squeezing. The fine polishing sponges were the exact opposite - They were thick with sludge and made the water black when I squeezed them.
As I said above I will redo this test in a few weeks when the filter is properly dirty - it was a few weeks, at most since I cleaned it last. I took out the purigen so I could medicate the tank. The issue is cleaning the debris that seem to settle in the tank even though there's quite a bit of flow and the obviously low flow in the first video.
Last edited by sundragon; 12-21-2012 at 04:52 AM.
Reason: Additional info