[freeztar]

Originally Posted by TerryPradha

At the end of the season I will test the ph of my TP mixtures. Then compare with the various soils I used for those mixes.

Cool! I'm about to start an experiment to determine the best ratio of char to soil for my soil type here. It would be great to compare results.

I wonder if it would be accurate to test the ph of groundup char itself?

Funny you should mention that. On my way home from work today, I was thinking about testing the pH of a pile of ground up char I have sitting in the yard. It rained yesterday, so the pile is still wet. I'll go test it right now and post my results in a bit.

[Essay]

Originally Posted by TerryPradha

Ok, thanks

At the end of the season I will test the ph of my TP mixtures. Then compare with the various soils I used for those mixes.
I wonder if it would be accurate to test the ph of groundup char itself?

...been watching paper dry over the past couple of hours.
My red and blue Litmus, and the Nitrazine paper all showed virtually no change relative to distilled water.

I'm thinking I should have soaked the char for longer maybe, before testing the solution. I'll try again tomorrow.

The char really likes the nitrazine paper; just grabbed right on to it. Fortunately it was just one side and didn't affect the color on the other side.

IMHO, char acts more as a buffer to either acid or alkaline (maybe depending on the source, firing temp., duration, etc.; but I don't think it's a major source or either acidity or alkalinity.

...activated charcoal goes straight into our fishtanks, regardless of the optimum pH level of a particular tank, doesn't it?
I could see that there is more potential for acidity (organic acids) left in the low-temp. charcoal; but these are not strong acids or bases.
IMHO?

[freeztar]

I tested my pile of charcoal with 2 litmus strips and both showed a pH in the range of 8-9. It's worth noting that this is store bought charcoal briquettes. I left them out in the open last summer to see if the rain would grind them down for me. The rain has definitely worked 90% of the pile into very fine grains.

I'd imagine that different char would give different results. Perhaps it has the most to do with residual plant resins. I recall Rblack talking about his pine needle char and how it was slightly acidic. In this case, however, the char was produced by pyrolysis (high temp.) so there should be no residues present.

[TerryPradha]

That is interestting. Pine needle chars being slightly acidic whereas briquettes are in the 8 or 9 range.
Are briquettes produced at high temps as the needles were?
This pyrolysis leaves little or no plant residue behind?

Talking about 'activated charcoal' for the fish tanks.
Now am I correct in understanding that this type of charcoal is fired at low temps?
Does this type have plant residue, that goes into fish tanks?

Sorry for the excessive questions, it is just that reading through the forum I seem to keep forming different ideas about which is what

Thanks guys, and it will be interesting to see if Essay's reading turns out different tomorrow.

I have started a pile using briquettes, mixed with various organic matter and a layer of garden soil in the middle of it. My other mixtures come from campfire chunks that I am assuming has all different levels of burn. Some of it crumbled in my hand quite easily and others turned out to be only slightly charred.

[Essay]

Originally Posted by TerryPradha

Talking about 'activated charcoal' for the fish tanks.
Now am I correct in understanding that this type of charcoal is fired at low temps?
Does this type have plant residue, that goes into fish tanks?

...btw...ran across this....
Wood ash, an organic amendment, is high in both pH and salt. It can magnify common Colorado soil problems and should not be used as a soil amendment. -from
Choosing a Soil Amendment

===
As to "activated," I think the more complete and high temperature the charring, the more activated it is.

I think the goal (in activation, not TP) is to get the carbon into it's most highly reduced, graphenic, state. Then, throughout the irregular structure (broken graphene), you'll essentially have naked (well, scantily clad) carbon nuclei projecting out into empty space (waiting, eager with anticipation, to be oxidized).

[freeztar]

Originally Posted by TerryPradha

That is interestting. Pine needle chars being slightly acidic whereas briquettes are in the 8 or 9 range.
Are briquettes produced at high temps as the needles were?

The briquettes were produced via pyrolysis (high temp) whereas the pine needles were produced via low temp.
I'll try to find the exact post for clarification.
EDIT: Found it!
http://hypography.com/forums/chemist...-charcoal.html

This pyrolysis leaves little or no plant residue behind?

Correct, pyrolysis leaves little to no residue behind. This is "activated char", the type used in medicine and fish tanks.

Talking about 'activated charcoal' for the fish tanks.
Now am I correct in understanding that this type of charcoal is fired at low temps?

See above.

I have started a pile using briquettes, mixed with various organic matter and a layer of garden soil in the middle of it. My other mixtures come from campfire chunks that I am assuming has all different levels of burn. Some of it crumbled in my hand quite easily and others turned out to be only slightly charred.

In a campfire situation, you will experience a variety of char effects. Using the "Popcorn tin" method of home-charring, outlined by David G Mills (http://hypography.com/forums/terra-p...tml#post162382), it's possible to create much more controlled circumstances (low O2) than an open campfire will allow.

[TerryPradha]

Thanks for the forum sites. This one I found to be disturbing.

Thanks for the website. I didn't find anything there but did find that hardwoods make soils have a higher ph the softwoods (conifers) and an interesting fact that hardwood increased the CEC of soils but conifer actually decreased it. This from "Ameliorating physical and chemical properties of highly weathered soils in the tropics with charcoal", Glaser, Lehmann, Zeck 2002

I thought it was the carbon that provided CEC rates. I didn't go to the article yet, but may have to see these ideas in context. I have a large pile of pine that I was thinking about reducing to char. But now I am not sure what I gain if I am reducing CEC.

[TerryPradha]

Originally Posted by Essay

...btw...ran across this....
Wood ash, an organic amendment, is high in both pH and salt. It can magnify common Colorado soil problems and should not be used as a soil amendment. -from
Choosing a Soil Amendment

===
As to "activated," I think the more complete and high temperature the charring, the more activated it is.

I think the goal (in activation, not TP) is to get the carbon into it's most highly reduced, graphenic, state. Then, throughout the irregular structure (broken graphene), you'll essentially have naked (well, scantily clad) carbon nuclei projecting out into empty space (waiting, eager with anticipation, to be oxidized).

Ok, thanks. That makes sense to me. It is the scantily clad carbon that does the filtering, so we would automatically eliminate the plant residue as much as possible. For that process.
In the TP idea we want to preserve some plant residue for the wee beasties.
[If I am following correctly]

What if, instead of leaving the residue of the plant, we went with the high carbon char. Then filled the char's condos with something other than the original plant material that the char was made from?
Does it work that way?

[Essay]

Originally Posted by TerryPradha

What if, instead of leaving the residue of the plant, we went with the high carbon char. Then filled the char's condos with something other than the original plant material that the char was made from?
Does it work that way?

I think that's valid. You could soak activated char in MiracleGrow and make a time-release fertilizer (I'm speculating).
Equally(?), used fishtank filter charcoal would be "charged" with "fertilizer."

...btw
My new pH tests looks about the same, fairly neutral.

See a "pH report" on the TP Blog (click on "Terra Preta Social Group").

[Michaelangelica]

Originally Posted by freeztar

It's an interesting question.
I guess the only way to know is to experiment and find out.

I don't know how char works on pH.
I think it may change over time.
Some timed experiments, testing every few months, would be a good idea.

An interesting article on soil just posted on The TP list
The future of dirt - The Boston Globe