I know this is an old thread to respond to, but . . . we have two large coil denitrators on our 360-ish gal system, with some modifications which I'll outline later. We (my son and I) proved that it works using store-bought
nitrate test kits, and I really feel that this is an important addition to any system. I think it's like having a massive
DSB which you force water through. Empirically, I feel that this type of device could eliminate the need for
DSB's or larger
live rocks. We are in the process of builing one for our separate 29 gal Biocube, which has a shallow sand bed and not much rock. Anyway, we are about to send water samples to the Aquarium Water Testing service to see if we can prove the results in a more accurate manner. Although I think the
nitrates are so low anyway that there couldn't be much difference between the "in" and the "out" of the denitrators. Maybe the Biocube will be more significant. I'll keep y'all posted!
Jay