# Old Akadama



## idris (26 Feb 2021)

Can Akadama get too old?


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## idris (8 Sep 2021)

Bump (... because I still don't know the answer.  )


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## PARAGUAY (8 Sep 2021)

I not sure if or how accurate but it is very inert so good fertilising is needed. Has it been discussed in "The Sòil Substrate" in tutorials  and Tom Barr discusses it on the Barr Report. Hope this helps


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## bazz (8 Sep 2021)

Hi,
It's abroad question:
Is it still unused in the bag?
Is it still being used in an aquarium?
Is it used and dried out in a bucket?
Is it wet in a bucket? etc....
For me (although I have never used it), if it is currently being used in an aquarium and as long as it still has it's original composition I would use it again to rescape. If it looks clogged up give it a rinse and shake in tank water. If its still looks dirty try a more vigorous method with tap water, still no luck, throw it in the garden and use some new.
Cheers!


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## zozo (8 Sep 2021)

I've used 40 litres of the extra hard type starting from back in 2015 I think, for several years, 4 or 5 in one aquarium and then reused this again in a different aquarium for a while without any issues. After I was done with it, meaning stopping with these tanks and not having another aquarium setup to use it in I used it in pots to grow plants in the garden. Actually still do have these pots with plants today growing pretty good.

What happens is when you poke around in it a lot some parts will turn to dust, but it remains clay... Gathering and reusing the dust is difficult, but if you rinse this out what remains can be reused. And it remains actually pretty hard to my surprise. Also what in the pots in the garden it still is hard Akadama.

I'm not sure about the soft type Akadama and how it is graded and if all graded hard is equally hard. It's a natural product and hard is dug up from deeper more compressed layers. So I guess there will be tolerances in hardness depending on this.

Anyway, I guess whatever you do, clay remains clay... And Akadama is a sort of clay, naturally baked and mineralized by ancient volcanic activity.

It's already pretty old from the bag...  And as long as it's a hard granulate I guess it can be used indefinitely. I see no reason how it could be too old if it remains in its shape and doesn't turn to mush.


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## idris (8 Sep 2021)

It's been in the tank for 10+ years. IIRC It's "hard" Akadama.
As much as anything, I was wondering about it's ability to facilitate (... oh jeeze ... what was the phrase I kept reading at the time I chose it ...) cationic exchange (I think that was it?) or whether it becomes (I'm guessing here) inert and no better than sand and gravel.
Our water is V hard, so I could imagine that (eg) the clay particles could become ionically saturated with some component of calcium carbonate, reducing it's capacity for more useful nutrient storage.
(Obviously I'm not a chemist, so this may make no sense whatsoever!  )


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## zozo (8 Sep 2021)

idris said:


> Our water is V hard, so I could imagine that (eg) the clay particles could become ionically saturated with some component of calcium carbonate, reducing it's capacity for more useful nutrient storage.
> (Obviously I'm not a chemist, so this may make no sense whatsoever!  )



Due to a computer crash, I've lost the links to scientific articles I saved about CEC and volcanic substrates... But from what I did understand from these articles is that CEC is a tad overrated property mainly used as an advertising yell on labels. And volcanic substrates have the worst CEC of all CEC substrates but seem to grow crops like a champ. 

Take for example growing plants on silica sand or silica gravel that works equally good, both have 0 CEC from the start and will never build any CEC up because it stays inert and never absorb anything. Then even if a clay granulate with good CEC loses this capacity over time and changes into an inert pebble. Then I guess nothing bad has happened that can not be overcome by adding fertilizer to the water column.

I guess CEC is of importance when it comes to growing crops in fields... But for aquariums, it's a somewhat interesting but also neglectable termology.

In the years I used Akadama I didn't experience the need for less fertilizer in these tanks...  Can't say it's good CEC did do anything for me or the plants.


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## ceg4048 (10 Sep 2021)

zozo said:


> And volcanic substrates have the worst CEC of all CEC substrates but seem to grow crops like a champ.


Hi Marcel, 
There are different types of volcanos and therefore different kinds of volcanic rock. The "worst" volcanic type your article might have been referring to would be perhaps be _some _types of pumice, but the material formed by lava has a fair to middling CEC. The worst material as far as CEC goes is sand. The highest is garden soil or humus. Clays types are typically better than lava types, and even among the clays, some are better than others.

You'd have to test the importance of CEC with a more thorough testing. I've read some studies where even though garden soil has the top CEC it can actually be improved by adding clays, such as perlite, but the clay particles need to have some very small maximum diameter. The reverse is also true. Organic matter added to clay improves the CEC of the composite. Aquasoil has peat baked on that both helps it's CEC and also provides carbohydrates for the bacteria. Of course, if using a water dosing scheme the nutrient levels in the water may overwhelm any advantage of CEC. Perhaps it's with leaner dosing that the advantage might be revealed.

Akadama is a good option and like any clay, as long as it doesn't collapse into mush, it still functions if clean.

Cheers,


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## zozo (10 Sep 2021)

ceg4048 said:


> There are different types of volcanos and therefore different kinds of volcanic rock. The "worst" volcanic type your article might have been referring to would be perhaps be _some _types of pumice, but the material formed by lava has a fair to middling CEC. The worst material as far as CEC goes is sand.



Hi Ceg,

The PC these bookmarks are on is dead, I would need to take out its HDD to see if I can recover this bookmark. And I saved it quite some time ago somewhere around 2015 when I first used Akadama and that CEC thing about it got me curious, so I started reading about it and found this article. I actually do not know if this is still online, could be long gone after these years. I give it a go and if it's still there I'll post it. The article had nothing to do with the aquarium it was all about vulcanic soils in general from different regions and also their CEC tested and all came back with a rather low number. 
The bottom line conclusion I could make up from it was that a good CEC might be helpful but isn't a necessity to farm crops as long as all nutrients it needs are available.

Then personally seeing a 1500 litre aquarium bursting with lush growing plants growing on plain sand only pushed me over the line not to worry about it anymore. And when buying aquarium soil that the Good CEC on the bag's label is something rather neglectable when it comes to growing aquatic plants. 

I also wouldn't know how to test it and or interpret and determine the results in what is what.


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## idris (10 Sep 2021)

Maybe I shouldn't have mentioned CEC.


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## ceg4048 (12 Sep 2021)

zozo said:


> Hi Ceg,
> 
> The PC these bookmarks are on is dead, I would need to take out its HDD to see if I can recover this bookmark. And I saved it quite some time ago somewhere around 2015 when I first used Akadama and that CEC thing about it got me curious, so I started reading about it and found this article. I actually do not know if this is still online, could be long gone after these years. I give it a go and if it's still there I'll post it. The article had nothing to do with the aquarium it was all about vulcanic soils in general from different regions and also their CEC tested and all came back with a rather low number.
> The bottom line conclusion I could make up from it was that a good CEC might be helpful but isn't a necessity to farm crops as long as all nutrients it needs are available.
> ...


Hi Marcel,
                Yes, I agree that fundamentally if the plants are being fed properly the CEC of the substrate is not nearly as important. I only mention it in case someone is doing a lean dosing. At that point the significance of the CEC increases.

Testing would be elaborate as the leaves would have to be isolated from the root so as to prevent foliar feeding if testing under water. I've actually seen such a setup. The testing sediments would be prepared by soaking them in a nutrient solution then the plants inserted. After a period the plant is harvested and dried. Then the dry weights are measured. This has to have statistical relevance so there would have to be many samples to compare the weights.

CEC is definitely measurable and each material has calculated values based on the amount of nutrient ions found on the substrate after being soaked in solution. Normally an Ammonium compound is used to soak the material and then it is washed, but some of the ammonium ions remain after the wash, bonded to the material via Van Der Waals. The density of the bonded ammonium is counted and the ion retention value determined.

So it's a very real property of soil materials but these types of measurements are beyond what we have the capability of.
In any case, most aquatic in their native habitat are really starved of nutrients because the water is devoid of nutrients, but they are able to eek out a living and do well if they are situated in clays soils, and that's directly attributed to the CEC of materials such as laterite and other clay types.

Cheers,


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