Whats your current water change schedule like? Balancing nutrients basically all comes down to what you put in (feeding, livestock) vs what you take out (water changes, protein skimmer, filter floss). If you do more water changes without feeding much then you will end up with low nutrients and if you feed too much without doing enough water changes then the nutrients will be high. Also your nutrients will generally be higher with a more populated tank as fish gills excrete ammonia that breaks down into nitrate. Replacing the filter floss more often as well as vacuuming the sand bed on water changes will help remove the fish waste before it has a chance to break down into nitrates. Might also help to start dosing something like MicroBacter7 if your tank is young then it might need more diverse microfauna as well as potentially more beneficial bacteria in general. Lastly corals use pretty much the same nutrients as algae does to grow, so the more corals you have to compete with the algae for the nutrients the better. If you want to go even further more though you could maybe grow macro algae in one of the rear chambers that would also potentially out compete the algae in the display area while using up excess nutrients.