For Biofiltration Chaeto (Macro Algae) is a popular choice. Very easy to do if your setup has some form of refugium or sump. All you really need is a grow light of some kind. If you don't have the space for even an HOB refugium then GFO (Granulated Ferric Oxide) is good for removing phosphates (although it won't affect nitrates much). All you need for GFO is a media bag and a place to put said media bag. When I had my 36 gallon bowfront I used to run a Chemipure Elite bag (mix of Carbon and GFO) in my Fluval HOB Filter and that seemed to work well.
Since I have a 29 gallon sump on my 90 gallon tank, I actually run both in my setup. I have a GFO Bag near my return pump and cheato in my protein skimmer partition. Here is my setup:
A month later this was how much that Chaeto had grown: