I was just wondering if anyone had any first hand experience with coil denitrators. I built one a few weeks ago and started it after a lot of research, but I am still unsure of a few things about them. What do you recommend for a flow? How will I know when to increase the flow? Is there a test for hydrogen sulfide gas coming out the return besides just smelling it, how about pH? Also is it necessary to supplement the denitrator with a carbon source like sugar or vodka and how do I go about doing that, and at what amount and concentration?