Converting BRS dual reactor to Bio Pellets?

I have been researching this because I just can't get my nitrates to an acceptable level. I almost went with vodka dosing (bought the vodka, got the syringes) until I wondered what to do if I was out of town for a week and you are supposed to dose every day. I currently have a BRS dual reactor with carbon and GFO. I want to convert it to run the bio pellets. Do you think I could run half the amount in each reactor, or just leave one reactor empty, or sell it and get a single? I also have mine running off of a manifold right after the UV. Any help is appreciated.