Looking for recommendations. Over the last 3 months I have been trying to control my Phosphate and Nitrate. I stood up a sulfur reactor and I know can control my nitrate. For phosphate I am running a GFO reactor. It working too good and I can’t maintain any meaningful phosphate. Any recommendations on how to maintain some phosphate.
If you quit all things that can eliminate po4 in a unnatural way, like GFO, adding organic carbon (a sort of natural export but uncontrolled) , I wouldn't immediately dose po4 when low values as long as you feed the tank, fishes and maybe also some organic coral food.
Your question is good because we know very well from scientific studies that ultralow po4 is bad for the zooxanthelle =bad for the coral. But we also know that coral is extremely good at extraction po4 if needed as long as its not true zero thanks to active transport channels. So ny opinion is:
1) to always be very careful with unnatural way to eliminate po4 (Like gfo and similar, carbon) and stop with these immediately if po4 is below 0.02
2) better too high than too low
3) ideal value? Like 0.04-0.1 (there is no benefits having excess of po4 either)
4) if between 0.00-0.02 but no unnatural methods that will bring it down further, I would not dose po4 but just feed fish and coral. If coral looks pale despite this, I would dose po4 up to 0.04.
Jonas