Id like to correct myself as im reading this i realized id be referring to the HPK product by roots organic, it has P, K, calcium, and magnesium in it where the HP2 is just P and calcium, also i would reccomend reammending element and supplimenting with HPK throughout because the element was designed to be reammended and will breakdown faster if you are feeding the NLS microbe tea, the microbes will be steadily breaking that down for the roots to uptake and wont last as long as you think it might.