I would recommend Rox.08 for carbon and RowaPhos for GFO
I use very little
Carbon: about a tablespoon per 50gl, changed biweekly
GFO: I dont use a measurement per say but I would say that I use about half of what the container says and change it every month. I also give it a good shake every couple of days to keep it loose.
I use a reactor. One reactor for each media linked in series. This way I can change each media separately. You can run both the carbon and GFO in the same reactor. Carbon on the bottom and GFO on the top separated by a sponge. Problem here is that you will need to change them both at the same time.that is good to know that i should give it a good shake every couple days. Do you use your gfo and carbon in a reactor or do you bag them?
I use a reactor. One reactor for each media linked in series. This way I can change each media separately. You can run both the carbon and GFO in the same reactor. Carbon on the bottom and GFO on the top separated by a sponge. Problem here is that you will need to change them both at the same time.
The shaking of the carbon and GFO is to prevent packing and channeling.