I have my usual summer bumper crop of SA and am once again trying to figure
out how to change this permanently. I know my pond does not circulate very
well (filter and waterfall both on the same end) and that my aeration isn't
that great (short waterfall), but beyond that I'm stymied.

My water is always clear and though the plants grow well, the older leaves
yellow. My nitrate levels are always 0. I add potassium regularly, and
have experimented with magnesium and iron occasionally. The plants respond
to one of these when I add them, but I have loads of SA in the shallower
parts of the pond, in the hyacinth roots, etc. I harvest enough to use it
as yarn - knit it into sweaters maybe? Paperweights?

Anyway, adding an airstone made no noticeable dent last year. All readings
are w/in normal ranges, but I remember reading once that if a pond is
nitrate limited, SA can out-compete for available nitrogen.

My plan is to reshape the pond for better circulation and hopefully better
O2, and perhaps up by potassium doses, since it makes more intuitive sense
that my pond is K-limited, but any other ideas?