That reactor with the nitrate sponge is a cause for concern I see. I used to use that stuff too, and only got negative results. Do you clean it regularly. I noticed all that stuff did was trap detritus, and didn't help with nitrates. I use that Matrix media in Fluval canister, which is pretty much a reactor, but I make sure I rinse the detritus off the media about once a month. I also have the media in my overflow section of my DT and do the same maintanence. The main difference between nitrate sponge media and the Matrix is that that material that the Matrix is made out of is much more porous, so bateria has more surface area to cling onto. You would be surprised at the difference in densities when you see them side by side..