From what I’ve read bio wheels contribute to increased levels of nitrates. I’ve struggled with my nitrates as I can’t get them below 20. I have a 2 month old 20 gal tank with 1.5” of live sand and about 15lbs of live rock, 2 perc clowns, 1 royal gramma, 10 nass snails, 9 blue hermits and 3...