Good to hear about the cyano and not good to hear about the stn but I was very interested in your AIO experience.
I have stripped PO4 too fast twice now while still stuck in the chasing numbers game over here. This time I was finally able to drop it slowly adding an extremely small amount of GFO and NOPOX 5ml a day for 3 days (this is below maintenance dose for my 150 gallon). I turned my GFO off as soon as I was under .03.
I'm also running AIO in a recirculating reactor but so far I've been unable to control PO4 without some level of help. I'm up to 1L, adding a second 500ml a week ago. My nitrates are lower than I want, down below 1 now, but all my SPS look healthy. My BFC was 1.0 but I am bumping that up ASAP.
Do you think I'll need more than 1L of AIO for ~ 150 gallons of water?