This test was not done after a water change, it was done on Saturday night towards the end of a normal week of EI dosing according to my schedule.
I have 3 dwarf puffers, 3 nerite snails, 5 or so amano and a handful of RCS. I clean the front glass every 10 or so days to get it crystal clear, so it's not a tremendous buildup or algae. I just like my tank to look spotless, and I face no other Algae. The only other issue was stunted tips on some of my rotalas, but I blame that on a week of having a dirty ADA diffuser with larger bubbles (which I fixed).
You can see how much phosphorus I already dose 3x a week. 13.5 mL... I think I'll up to 18mL or 20mL and then take a few more test readings this week. How does this sound?