Re: iron uptake/degradation

>From: krombhol at felix_TECLink.Net (Paul Krombholz)
>Date: Sun, 7 Apr 1996 19:35:28 -0500
>Subject: Re: EDTA photodegredation
>When I was growing aquatic plants in algae-free culture back around
>1966-68, I noticed that I had a precipitate in flasks of nutrient solution
>plus iron EDTA that had been exposed to light, but no precipitate in
>identical flasks kept in the dark.  However, enough iron stayed in solution
>to grow the plants satisfactorily.
>Currently, I am using iron DPTA, (diethylenetriaminepentaacetic acid),
>which appears to stay in solution a lot longer.  CIBA-Geigy, agricultural
>chemicals division,  makes it, but it is hard to find in your average
>garden store.

Does any know the physiology of (or ran tests on) iron uptake vs. light.
Also, when iron is added in larger doses on a weekly basis, how much of the
iron is utilized on (and how does the water concentration vary between) day1
vs. day 7.

For daily or weekly dosing,  is it better to add iron first thing in the
morning or just before the lights go out?

BTW, Tropica Master Grow contains HEEDTA ,DTPA  and E123 .

Usually with lots of questions and lazy to find the answers

Neil Frank, TAG editor    Aquatic Gardeners Association    Raleigh, NC USA