Sponges clogging sponge...
 

For whatever reason sponges really really love growing in the sponges in my TLF 150... It's to the point where after about two weeks the sponge gets so clogged up it severely reduces the flow (With the very scientific measure of seeing how fast the output fills a measuring cup). Does anyone else have this problem? Here's a pic I took today for fun

http://farm7.static.flickr.com/6066/...9a698da872.jpg

I had that issue while running bio-pellets. Since I stopped using them, no more problems.

Yes same here. I have a canister filter with a sponge at the input and it is fully covered with tiny white sponges like yours. When I change my filter media it is always full of these little sponges inside. I guess the fast current in there and the nutrient trap is attracting them.