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Re: NH4 and algae

> From: "James Purchase" <jppurchase at rogers_com>
> Subject: Ammonium and algae

> Interesting tidbit....and one more "point" for Tom Barr....
> http://www.mwra.state.ma.us/harbor/html/20010927bh.htm
> "...Ammonium is the main form of nitrogen in secondary treated wastewater,
> and is the form of nitrogen that most stimulates excessive growth of algae."

If you look at new production in oceanic pelagic salt water ecosystems, NO3
inputs are correlated with _new production_ while NH4 is regenerated within
the trophic food web.
> Tom has been cautioning us against using fertilizer sources which contain
> NH4.

Well it is the reason for not having so many fish that it exceeds the NH4
uptake capacity of the plant load. Healthy plants possess higher NH4 uptake
rates of NH4 than that of stressed plants. You can test this idea for your
self fairly easily.

Add one feeder fish or minnow etc one at time till you start to see algae.
Test the PO4 and test the NO3. You will not see a a large increase beyond
what you can add inorganically with KNO3, KH2PO4 etc. But the NH4 and urea
is the first product that comes out of these fish/critters etc, not NO3.
This NH4 can exceed the uptake capacity of the plants and when this happens,
you get algae.  
I can add PO4 till I have 2ppm, NO3 up to 20-40ppm range, but I add too many
fish or an inorganic NH4 source beyond trace tiny amounts, I get at least
2-5 species of nasty algae.

Tom Barr

> James Purchase
> Toronto