protein skimmer

[pluk1992]

protein skimmers reduce nitrates right because water cahnges dont help much at all

 

[malkore]

protein skimmers help remove the DOC's that break down into nitrates.
water changes also lower nitrates, assuming your replacement water is clear of nitrates (if it's not, I recommend RO/DI water for water-changes)

 

[morphviper]

macro algea will remove nitrates at a slow rate.