Bright Red Clay and Iron contained within

[AquaticJim]

I have gathered some very red clay, it's very red and stains ones hands. I have put some in a glass beaker stirred it daily and added more each day for a week and then waited for the clay to settle to the bottom of the beaker and the water to clear.

Taking a sample of this water and testing it for Iron with a hobbiests test kit results in a zero reading.

So -

Does this red clay in fact contain no iron within it?

or

Is the iron (if any) not able to be picked up by a hobbiests Iron test kit? (I can dip a hair in Seachems Iron and drop that in the Iron Test water and the reagent immediately turns dark pink).


Is this clay worthless in trying to make DIY clay balls for root feeders as it is (without the addition of added ferts)?

Maybe I should just stick with Seachems Root Tabs, though they work out expensive, I'm getting results from them.

Thanks,

Jim

 

[Biollante]

Ferric, Not Ferret Oxide

Hi Jim,

Hi Jim

Hi Jim,

Once again I will yield to the smart people…


If it is good old American red clay, great for making firebricks and such…


If it is good old American red clay then the red is a result of Ferric Oxide, Fe[SUB]2[/SUB]O[SUB]3[/SUB], I seem to recall 1.1% or 1.4%, I’ll have to look it up later.

Ferric Oxide is not very water soluble at all, probably why it is a good long term iron source, I am not sure about that…


You will need to wait a very long time or chelate (complex) the Fe[SUB]2[/SUB]O[SUB]3[/SUB] if you have some EDTA or whatever around that is fine, if not lemon juice or a crushed Vitamin C tablet should work. Mix it up, give it a few minutes and you should get some kind of reading from your test kit.



Hope this helps or someone that better educated can weigh in…


Biollante

 

[Biollante]

Not A Hero In Sight... Just Me & Thee...

Hi Jim,
I suppose without the aid of the smart, we could figure it out.:gw

Into a one liter container place one gram of your suspect clay sample (baked); add twice as much lemon juice[SUP]*[/SUP] or a gram of crushed vitamin C tablet or 2/3 gram EDTA if you have it (the amounts of our chelate are not critical as long as there is more than enough).
{It is often easier and more accurate to make more concentrated solution, say 10 grams or 100 grams then dilute.}

Add enough distilled water to make one liter of solution.

Mix well.

Assuming your test kit is reasonably accurate your solution should measure around 10-ppm Fe[SUB]2[/SUB]. (Arithmetically 9.8-ppm would be 1.4% Fe[SUB]2[/SUB]O[SUB]3[/SUB] and 7.7-ppm if it were 1.1%, I am pretty sure I recall 1.4%, still have not found my reference.)


Biollante
[SUP]*[/SUP]Lemon juice contains about 0.2-ppm Fe[SUB]2[/SUB], that is statistically insignificant here.

 

[AquaticJim]

Thanks Biollante, thats given me heaps to think of and muck around with

 

[Biollante]

All Kidding Aside; I Am Curious

Thanks Biollante, thats given me heaps to think of and muck around with

Hi Jim,

If you try any of it or figure the stuff out I would love to hear your experience.

Good[SUP]*[/SUP] or bad.**

Biollante
*Of course the result of my advice
**Obviously you messed up

 

[AquaticJim]

I did this and still didn't get even a hint of colour on the iron test.

Just wondering how long I was supposed to bake the clay for?

 

[1077]

I made some root tabs with red pottery clay and placed a few granules of Osmocote plant fertilizer inside each plug.
I then baked these plugs at 325 degrees F for 30 minutes. I then let them dry even further for about a week.
I used red pottery clay cause I had read somewhere that it contained Iron.(perhaps while reading bout mineralized soil?)
Anyhoo,, about three months after pushing the plugs into the substrate,,I removed a bunch of leopard vals that were getting away from me and plugs in this area were still not quite dissolved but enough so that osmocote was able to disperse?dissolve?
Maybe test some red pottery clay? I found mine at hobby store. (maybe it didn't have iron but plant's sure liked the plugs)

 

[Biollante]

A Post in Search of a Thought


Hi Jim,

I had neither the wit nor wisdom to ask if the suspect clay has been fired. If the clay has been fired at something over 1100C (which is pretty much the definition of firing) the chemical structure is changed and I think the iron may be lost. I am pretty sure it is chemically inert, the advantage is the larger (I think ¾ larger) pores increasing the cation exchange capacity effectiveness.

As far as I understand “baking” is at 120 C (250 F) until hard. I think the idea of the baking is to drive off the water and destroy organic material, “mineralizing” it.

Honestly I have found cheap kitty litter soaked in water for a couple of weeks to be as effective as any of the clays I have used, including the much ballyhooed Akadama clay, fired and unfired.

Clays will turn your substrate rich over time as a result of the high cation exchange capacity. The iron oxides in the clays are relatively low, actually very low, cation exchange capacity and the iron oxide is in a form that is not readily available to plants.

I kind of like 1077’s idea, the Osmocote has chelated iron.

I have tried James idea adding Calcium carbonate, Magnesium sulfate and Potassium sulfate. I see no reason you would not be able to add iron. http://www.theplantedtank.co.uk/akadama.htm

It makes a very rich substrate (I am sure James is mimicking a commercial substrate), my sense is that ultimately if you want an enriched substrate you are better off with whatever clay, worm poop and sphagnum moss.

Sorry for the rambling…

Biollante

 

[AquaticJim]

Just rolled some of this clay into small 1cm balls.

Held a magnet over them and they jump straight up and stick to it.......so there must be iron in there!