Hooked up my carbon filter today. I'm only using it to scrub the air on a timer. Decided to poke a few holes in the ducting to help move scrubbed air around my plant. Added the other fan back in to keep air circulating. Since I don't have fresh air coming in I plan on using a supplement for co2. What are you guys using? It's only a small 2×2×6 tent with one plant and running a 150w HP's light.