Re: Peat

[Doug Brown <debrown@kodak.com>]

>>   <snip> As we're getting off-topic <snip>...

>I beg to differ.

OK ... on to the Peat Wars! I failed to incite a riot on
rec.aquaria.freshwater.cichlids by claiming I cycled my tanks by spitting
into them every morning, but maybe this will be the one.

>>doug wrote:
>>
>>  ><snip> The decrease
>>  >in pH in peat filtered water is almost completely due to leaching of
>>  >existing tannins from the peat.

daktari said this, not I. In fact I disagreed. I disagree with the "almost
completely" statement.

>The pH and hardness each drop for the following reason.  The "active
>ingredient"
>in peat exchanges two hydrogens for each calcium. The removal of calcium
>lowers >hardness, the addition of hydrogen raises acidity (lowering pH).
>This is the >important difference between peat and the quasi-softening of
>household softeners >which exchanges calcium with sodium.

Ion exchange and leachable acids both contribute to the overall acidity of
the various peats. As does the remaining plant tissue, the environmental
conditions the peat came from and more. The chemical nature of peat is
complex, and not fully understood at all. In my grossly oversimple universe
I look at moss peat as an "acidic ion exchange sponge". You take an acidic
material out of its acidic medium and dry it. When you put it back in
water, presto, acid and ion exchange. With some leachable organic acids. As
this comes from a Ph.D. chemist (yes, me) you're probably quite disgusted
by this concept. Check the link I gave you for a little more information
here.

>The topic centers on Apistos and similar dwarf cichlids.
[snip]
>I think discussion about peat and how it makes water more conducive for
>Apisto-keeping is quite
>relevant to each of us who subscribes to this list. [snip]

OK by me! I'll contribute what I can, and am certainly interested in
learning more. What trace organics are in native apisto waters? What are
the compenents of and differences between various blackwater extracts and
peat (sphagnum or whatever) filtered water? What really works? Those are a
few of my questions.

- -Doug Brown
debrown@kodak.com