My XP3 is on my 55gal. There are actually three media baskets. The bottom basket contains coarse sponges stacked together, actually two very coarse and two very slightly finer, but still reusable. The middle basket contains ceramic noodles in mine, as well as a mesh media bag of crushed coral to boost my KH
(heavily planted CO2
injected high-light tank - most folks don't require this) and the third basket contains floss.
Each basket has a divider, which you could use to divide each basket up for a total of six compartments, but who needs that many different types of media? Carbon is not necessary, and it is no longer effective after about 5-7 days, so I don't use it. If you have room, I'd add more biomedia, like bio-balls, or Eheim ehfisubstrat.