wrote:
I was thumbing through a well known, but older Limnology text
(Hutchinson, 1975, Vol 3 Limnological Botany pg 351-357) when I saw a
nice graph showing growth rate vs NO3 concentration.

It seems Paul had found that 20-80 ppm and above was the ideal range
for submersed plant growth(Vallisneria americana) back in the
1960's(1966). I suppose I redisocovered this range(20-75ppm)
independently some 30 years later thropugh trial and errors.

snip

Thanks, Tom!
I ventured onto Usenet again on a late-night impulse and here's some
real science. :-)

The info about HAT and NAT transporters has some interesting
implications. I had always assumed that it was OK to allow nitrates to
rise and fall with water changes. Looks like if NO3 falls too far,
plants induce HAT transporters and the next dose of fertilizer does no
good. Interesting...

I wonder how fast algae adapts vs. higher plants.

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