Too much filter media in BC29?

Just curious, in my Biocube 29 I run an inTank media basket with filter floss on top, purigen in the middle, and chemi-pure elite on the third shelf. Next to that (and still in the second chamber) I have a media bag with roughly 3/4-1 liter of Seachem Matrix.

Is the Matrix too much? Is there something else I can run there that's better? I have no algae problems or other issues. I just became curious when reading others' Biocube setups and only see the inTank baskets without a reference to Martix.

Thank you.