Howdy,
I'd use some laterite and sand ... old school
I have to mention that I once used that on my 80 gal. It takes weeks for the water chemistry to equilibrate, which I didn't know at the time. Hardness went down to zero within a day, predisposing the system for a pH crash. I changed 60 gal daily for at least a couple of weeks... Then came red algae, later blue/green. I threw ADA out after one year of desperately trying to get it to work ...

Don't get me wrong, Amano shows us how nicely it can work, it just didn't work for me.
HarleyK