# natural red clay?



## humdingerx (27 Feb 2015)

Would someone be so kind as to link where I could get some cheap iron enriched red clay? I just need a small amount so don't need large sacks. It's just to have a decent source of iron for some plants... there are various clays on ebay and I'm not sure what would be best (or if the red ones are just dyed??)


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## Edvet (27 Feb 2015)

http://www.aquariumbemesting.nl/nl/onze-producten/bodembedekking
Clay and laterite, mix them. I am sure he will send to the UK, mail him.


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## ceg4048 (27 Feb 2015)

...or, for less than £4 http://www.kaizenbonsai.com/bonsai-soils-small-trial-packs

It's doubtfull that anyone dye's garden shop molar clay. The dye would cost more than the clay....

Cheers,


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## dw1305 (27 Feb 2015)

Hi all,
[quote="humdingerx, post: 390317, member: 13093"(or if the red ones are just dyed??)......could get some cheap iron enriched red clay?[/quote] Any red clay will do, it isn't dyed it is just that the iron is in the oxidised FeO3 (ferric) form. Most blue-grey clays are also iron rich, they are initially grey because they have been water-logged, and the iron is the FeO(H)2 (ferrous) form. This is also why bricks are typically red, when you fire the clay any ferrous hydroxides, or oxides, are coverted to ferric (Fe(III)) oxide. 

The reasons that the clays are iron rich are two fold, one reason is that iron Fe++(+) is the most strongly bound cation, and the second is that iron oxides and hydroxides are insoluble, and once they formed they can't be leached. This is why ancient tropical soils in area of high rain-fall are "lateritic", only the insoluble aluminium, silicon and iron compounds remain.

That is also why the amount of iron in the clay isn't particularly relevant, this is because it is all insoluble unless you have an acid, anaerobic sediment (with negative REDOX values) where microbial reduction of Fe(III) can occur.

Adding a chelated form of iron to the water column (FeEDTA etc.) is a more efficient way of adding plant available iron, although if you have a fairly mature planted tank its likely that some iron will become available in the rhizosphere in the substrate.

There is a good article on <"iron"> via the ever erudite "Skeptical Aquarist".

cheers Darrel


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## humdingerx (27 Feb 2015)

Good info from everyone, especially about water column additive there. There's a lot of different colour clay on eBay which made me think those ones are dyed.

Plenty to chew one though, thanks


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## EnderUK (27 Feb 2015)

Got mine from Bath potter's supply. The ebay stuff isn't real clay or at least the stuff I found wasn't. I won't be bothering with clay again though, to messy.


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## dw1305 (27 Feb 2015)

Hi all,
Any clay will do, I always just go and dig some up (I go and get some acid clay from the gault clay / green-sand to the east of Corsham, as it is all limestone locally) but pottery supplies are a good source for cheap red clay. 

Cost is about £20 for 25kg delivered of "Red Terracotta Earthenware Clay".

We had a thread a while ago (I've just found it, and it is almost 5 years ago) that covers this area pretty thoroughly.  <"Darrell's soil thread..".>, and the thread it was spun off from <"How its made - Oliver Knott........">

cheers Darrel


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## Tim Harrison (27 Feb 2015)

I'm lucky I just have to pick it up off my herbaceous boarders Although that's unlucky from a gardening point of view


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## kirk (27 Feb 2015)

Troi said:


> I'm lucky I just have to pick it up off my herbaceous boarders Although that's unlucky from a gardening point of view


Glad I'm not your gardener, I can dig 6 ft down with a bucket and spade in  our garden anyone want any sand.


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