For what its worth, I've always gone with one of these.
The same one's actually bounced around from my 10 gal brig tank to my 30 gal community to now my 15 gal tank. Its currently being used on an AC 20 and I dont see much affect on flow or overall filter performance. Easy to clean and doesnt clog if cleaned regularly.

The same one's actually bounced around from my 10 gal brig tank to my 30 gal community to now my 15 gal tank. Its currently being used on an AC 20 and I dont see much affect on flow or overall filter performance. Easy to clean and doesnt clog if cleaned regularly.