I am debating this and was wondering if anyone does not run carbon on their tanks. My tank is fairly new and so far no signs of any problems and the water params are where the should be. I thought of running a reactor with phos/carbon but now I am not sure if it is necessary. The last test I did showed no phosphate or nitrate or ammonia. My last two tanks I used it but couldnt really see a difference. All water is RODI with 0 tds and I do bi-weekly water changes. Any thoughts on this?