Nitrate issues

If you have enough established LR, that will go a long way in denitrifying your water. But if you depend on that alone, you need to feed sparingly and maintain some kind of filtration. On the tank I maintain, when I took it over, I did a series of 40% PWCs (125g tank) to get Nitrates down from 160-200 to around 20, and the LR and skimmer took the rest down. If I shut the skimmer off, it started to creep up again. As soon as I put the algae scrubber on it N hasn't ever shown up over 0.2ppm and that's the next day after screen cleaning. I disagree with the DSB statement by Melev but I guess that's preference, DSBs have their up and down sides. Macro is almost always beneficial but a scrubber is basically that amped up because of proximity to light and high laminar flow which means better/faster nutrient export.