I agree with your friend, LR
is a much better biological media then are bioballs. You can fill up the filtration chambers in your aquapod with LR
rubble. See if any of the Lfs
in your area sell rubble rock, it is just the broken pieces of LR
in the bottom of the curing bins or shipping boxes. Make sure it is fully cured before you add it to the tank. If you are also using sponge blocks and ceramic rings (pretty standard in these kits) I suggest you ditch those as well.
The first concern is to address the detectable NO2
. The only acceptable reading is zero. How old is the tank? How long have the fish been in it? How did you cycle?