There is a high flow carbon based filtration system called a hiatt filtration system. But it requires massive amounts of carbon and a high flow pump.

Removal rates depended on the system variables. On a new start up on my 120, I ran a diy dual reactor with about 5 liters of sulfur media with peak no3 levels of 40ppm. At about 2 drops per second, it had no3 levels down to 20ppm after 3 weeks, and then dropped the remaining levels to 1-2 ppm after another 2 weeks.

Flow was upped to 3-4 drops per second after 15 ppm and the volume of media was reduced to 2.5 L.