From the PPS website:
PPS-Pro Solution #1, 1ml per 10 gallon or 40 L
PPS-Pro Solution #2, 0.5ml per 10 gallon or 40 L
Water change 50% once a week
This limits water column nutrient levels to 14 ppm NO3, 1.4 ppm PO4, 18 ppm K, 1.4 ppm Mg, 0.7 ppm Fe(TE).
It seems the difference between PPS PRO and 'EI' is small and mostly the ratio of N to P.
We may have to get @Edward
to weigh in here, but if I go to the calculators (RotalaButterfly and Zorfox) and use the daily dosing recommendations, I get EI as being dosed at over three times what PPS is dosed for NO3, even accumulated. PO4 is 6x higher EI:PPS. Am I missing something?