Re: UV sterilisers & macronutrients

[Paul Sears <psears at nrn1_NRCan.gc.ca>]

> From: "Newsletter " <Newsletter at brazeltonhotels_com>
> Subject: RE: Aquatic Plants Digest V5 #16
> 
> A long long time ago, Kevin Conlin of the Conlin-Sears study on PMDD
> wrote:
> 
> > The new formula is 1tbsp trace element mix, 1tbsp epsom salts, 2tbsp
> > KNO3, and 2tbsp K2SO4.  My original formula was developed while I was
> > using a UV sterilizer.  When I turned off the sterilizer, I needed
> > much less PMDD to maintain my iron levels, and the plants ran short
> > of macronutrients, primarily K.  I cut back on the epsom salts because
> > 1tbsp seemed to work just fine; no sense adding more than necessary.
> 
> So in a short answer, what impact does a UV sterilizer have on
> macronutrients?  

	None.
> 
> Is the UV sterilizer breaking down potassium thus the increase in the
> ratio of KNO3 to K2S04?  Or "What" is causing the perceived shortage of
> K when a UV sterilizer in running?

	The point was that the UV steriliser seemed to be rendering
micronutrients unavailable.  When it was turned _off_, Kevin was able
to cut the dose of "PMDD" without running short of trace elements,
and the reduction of dose caused the potassium shortage.

-- 
Paul Sears        Ottawa, Canada