I have a Marineland Penguin 330 on my 29g FW
I have had the tank set up for a year in January. Ive had tanks my whole life, including my last tank, a 55g FW
setup. I used Penguins on that tank too.. I do a 30% water change every Tuesday.
I replaced the filter cartridge 2.5 weeks ago because the old one was 'full' and water was going out the overflow. I checked it tonight - its full again and overflowing
Ive NEVER had a cartridge go 2.5 weeks and be toast. Quite the contrary actually. My cartridges last 3-4 months usually!
It appears there is some kind of brown algae growing on it. I have no algae problems in my tank at all. I dont overfeed. I occasionally fast the tank (1x per week). I cannot understand why the cartridges are clogging all of a sudden!