Review on Marineland Cartridge Refill Penguin Filter by Amy Young

I use this one filled with crushed lava rock in addition to the regular filter (which I never change until it falls apart). I have a pair of Penguin 200's. They are great filters but the wheels keep stopping. I don't worry about it anymore because lava rock is a great bioenvironment and I can use another tank with it right away. At first I tried to fill it with peat, but everything comes out. I could try putting the peat in a knee high nylon bag first and dividing it between the compartments.