I have a Marineland® Penguin® Bio-Wheel Aquarium Power Filter (100B, I think) and I'm not sure it's working properly in my 20Gal. tank.
I have 6 Corys, 14 Tetras, 1 Rafael, 3 Cherry Barbs, and 4 GloFish.
No live plants.
Air stone made for a 30 Gal.
Filter and heater came with the tank.
I am constantly changing replacement cartridges, about every 5 days lately. They are supposed to last 2-4weeks.
I know I have been over feeding my fish the last few days, but have gone back to their normal amounts.
So my question is what is a better filter I can have that won't cost me as much each month? Also what is the difference between all the different types of filters out there. Before anyone answers these questions, I feel the need to mention I am a graphic design major, so "speak" in less "technical" terms. I should also say I'm in college and have a limited budget, so a $100 filter is not an option for me at the moment.