Perhaps the majority of organic compounds present in an aquarium will contain nitrogen. Proteins, especially, are loaded with nitrogen, with every amino acid having at least one nitrogen atom and some have 2, 3, or 4 (arginine has 4).
GAC is a good way to remove many organics, and should reduce DON. Skimming may also work very well.
I'm not a fan of ozone, but it should work to reduce DON. The nitrogen-containing organics may be more likely to be consumed by bacteria after being broken up a bit with ozone.
The reason I ask is that I have a system where the DON went from 18.44 to 32.66 in three months. The nitrate went from 6.8 to 63.22 in the same period. All values are uM.
Not that I know of. The only thing different was that activated carbon was removed since the bag it was in started to break and release the grains in to the sump and into the pumps. I need to figure out a better method.
