[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Substrate iron

Bob Dixon wrote:
[Iron availability is affected by]
> >  2) the presence of small particles of stable organic matter such as
> >  peat. These peat particles maintain reducing environments
> >  (micro-environments as described by Roger Miller in a previous email
> >  several months back) which solubalize iron and provide a source of
> >  organic Fe complexes which help solubalized iron be transported by
> >  diffusion to root hairs. Only a very small amount of peat or other
> >  stable organic material is necessary.<snip>>
> So if I use redart at a 200 mesh (about like flour), with its 7+% Fe2O3, and
> add peat into the substrate, I should be able to get a very long term iron
> dosing, possibly even too much at first.  When the initial humus and tannins
> wear out, will the peat continue to function as a reduction "catalyst"?

If the clay is fine texture enough to use for pottery, then I think it
has very small particles; probably smaller than flour. That should be
good. I tried to use 5% peat by weight in the middle layer but this
seemed to be more than necessary. My best guess is that 0.5% - 1% by
weight (about one cup) should be sufficient and hopefully avoid high
levels of tanins which is the real problem on startup. Perhaps
preleaching the peat would also help. I think its really the amount of
dissolved organics in the water which is causing the high iron levels.

Sorry, I can't help with your other questions.

Steve Pushak                              Vancouver, BC, CANADA 

Visit "Steve's Aquatic Page"      http://home.infinet.net/teban/
 for LOTS of pics, tips and links for aquatic gardening!!!