I'd like to hear your thoughts of the relationships of these 3 parameters. For example, I've seen recommendations to adjust nutrient levels upwards if running high alkalinity, which seems to defy Liebig's Law of the Minimum which states the rate of photosynthesis is regulated by the least available nutrient, not the most abundant. In other words, alkalinity, acting as the carbon source for photosynthesis, doesn't matter if phosphorus is the limiting factor. Unless you're suggesting alkalinity has an effect unrelated to photosynthesis.