Thanks for the information, Jason. There may be something to the phosphate
buffer theory. I've never used a phosphate buffer, knowingly - but that
doesn't mean I'm not creating my own, somehow. Yes, I have incredibly hard
mountain well water (KH - 16, GH - 20). There is no agriculture or other forms
of human contamination above me to get into the water table (shallow improved
spring) but there's a lot of potassium getting in which could be from decaying
veg. matter in the forest. In general, my phosphate level measures higher than
NO3 level which the plants keep at zero. I hope to fix that shortly, if I can
get some of Seachem's Flourish Nitrogen. Its nice to know this isn't the slime
from an alien algae or bacteria, with or without a green card.