When my phosphates are below this ratio I either feed more Nori (or leave it in the tank longer) or do reefroidsMike Paletta did a survey during the pandemic of many peoples tanks who had very successful coral growth, and the common denominator was even though some people ran high, medium or low nutrients, they all had some and the ratio of nitrates to phosphates is 100:1
This was also echoed in Fauna Marin’s database of research. My nitrates stay around 8-10 and phosphates around .08-.1