i have an aquaclear 50 on my 14 gallon. i use the foam on the bottom, some cheap poly fill in the middle, a small bag of carbon, then the bio media. i added more bio media though to what they gave me- just did'nt seem like enough!
for the carbo, i use the pellets in an orange bag- you know, the ones for sale at the grocery store that you buy that round shaped fruit in? yeah that and it works great!