Toss out the Marineland filter cartridge, then stuff one or two Fluval replacement sponges inside the media box. The sponge will absorb much more of the gunk and provide better filtration. To clean, turn off pump, squeeze out sponge in old tank water, then place sponge back in media box. There still will be a little gunk residue shot back into the tank but probably not as much. I converted my ancient Marineland 280 bio-wheel to filter sponges years ago. No more expensive replacement cartridges. Lol.