Nitrate increases zooxanthellae population density and reduces skeletogenesis in corals.
To reduce nitrates in the aquarium:
-Do larger, more frequent water changes
-Reduce bioload and/or reduce feeding
-Carbon dosing: try a liquid nitrate remover or use biopellets in a media reactor
-Start a refugium or algae reactor
-Wet skimming
Test frequently for Nitrate on your ReefBot using Tropic Marin, Fauna Marin or API to keep the levels under control.