What is the best media for refugium sump?

[szambodi]

Hello, i have a refugium in my sump and looking to get rid of as many nitrates as I can. What is the best to use? Thanks for any input.

 

[s_kelley]

Cheatomorpho

 

[don in mass]

1+cheato ,Purigen by seachem, Chemi Pure ELITE by Boyd Enterprises

 

[Turbosnail]

I use Cheatomorpho and rubble rock w/ hermits and snails.