Glad to hear, what aminos are you using? I am using Korralin, and also reefbooster vials once per week(prodibio). Are you using any carbon sources such as vodka, sugar, vinegar, or any other c-source products? I know you run GFO and GAC in reactors, if you are using c-sources, I would discontinue use of GFO... I am finding that you have to find the exact balance of nutrients, too much, frequent glass cleanings of filamentous algae. Too low, paling or slight bleaching of the corals. So, I have personally found that some level of PO4 must be present in order to attain this balance. BTW, you tank is so clean and pristine. Corals are looking nice as well. Keep up the great work!