# Synthetic Terra Preta in the Aquarium (DIY Amazonian Black Earth)



## xenxes (Dec 22, 2011)

Did some Googling on this and not much discussion, so I thought I'd start one! 

Why buy expensive ADA Amazonia perfectly baked pellets when you can make your own?

*What is Terra Preta?* - it's nutrient rich Amazonian soil that has retained its fertility for thousands of years.



> Terra preta (Portuguese pronunciation: [ˈtɛʁɐ ˈpɾetɐ], locally [ˈtɛhɐ ˈpɾetɐ], literally "black earth" or "black land" in Portuguese) is a type of very dark, fertile anthropogenic soil found in the Amazon Basin. Terra preta owes its name to its very high charcoal content, and was made by adding a mixture of charcoal, bone, and manure to the otherwise relatively infertile Amazonian soil. It is very stable and remains in the soil for thousands of years.[1][2] It is also known as "Amazonian dark earth" or "Indian black earth".


http://en.wikipedia.org/wiki/Terra_preta

TL;DR version:

Basicaly, Terra Preta is soil with a high charcoal / carbon content. The charcoal acts as a nutrient buffer. By first saturating the charcoal with nutrients from decaying organic matter first, it can then slowly leech the same back to plants over time. This carbon is self renewing in a sense, because microorganisms dying in the porous surfaces of the charcoal adds additional carbon content. The high carbon content helps stabilize soil, and therefore water parameters in the long run. Because of its buffering capacity, the carbon creates a more forgiving environment to over/under fertilization, i.e. too much fish poo.

I have had great success with using charcoal as a buffer in planting orchids and several carnivorous species that are highly sensitive to nitrogen burns. They've thrived and flourished despite sporadic over/under fertilization. I think the same will translate over to a planted tank. 

I'm thinking of using a synthetic concoction in all the new tanks I'm starting, in order to increase stability.

(1) The synthetic Terra Preta (for low PH) will involve primarily:

- Natural Wood Charcoal (not activated carbon, which is more porous, though that can also be used and I imagine takes longer to saturate and may not leech as readily)
- Peat Moss (for PH buffer)
- Cow Manure (macro nutrients and quick start for saturating the charcoal)

(2) Optional but probably desirable additional supplements:

- Bone Meal (micro nutrients), i.e. grind up bone from your eaten chicken wings and t-bone steaks
- Compost (mostly bananas, egg shells, coffee grinds, tea leaves & yard trimmings, for additional nutrients and binder)
- Crushed Coral or Diatomaceous Earth (micro nutrients, particularly silicon)

(3) Not decided on these yet:

- Additional long fiber spaghnum moss on the substrate surface to decompose and add CO2
- Activated carbon to reduce tannin leeches of the long fiber moss, but my current inclination is that too much activated carbon will absorb too much, cancel out my desirable low pH, and is not a good idea. If I use any it will be in minuscule amounts
- Crushed Terra Cotta (not sure what this does yet other than additional porous buffering, but it's found in natural Terra Preta, there is a soil conditioner called "Turface" mainly to combat soil compaction; will probably not use since charcoal already helps with compaction)

(4) For funsies, I'm going to add a serving or two of dog poo, as a tribute to DogFish, my dog is also on a BARF diet

The nutrient buffering capacity can also be applied to high PH tanks. For high PH tanks, I would remove the peat moss, use chicken manure and higher volume of calcium carbonate, montmorillonite or bentonite clay, crushed limestone, extra volume of crushed coral and DE.

_*Warning/Disclaimer*_: I'm experimenting with %s and chemistry of this concoction, try it at home at your (plants'/shrimps'/fish's) own risk. Also, do NOT add straight charcoal (especially activated carbon) into your substrate as an amendment, in the short term they will simply suck all the nutrients out of your substrate and the plants will suffer as a result. You need to saturate the charcoal first, such as in a manure and/or urine marinade.


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## Monster Fish (Mar 15, 2011)

Nice write up. I've used a similar mix sans carbon and the results have been great. Are you planning to use raw or composted cow manure? For the compost, you can try replacing them with worm castings.


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## xenxes (Dec 22, 2011)

I think anything available from Home Depot and Lowes is already composted. For simplicity sake I think the cow manure + compost blends will do the trick. I'm throwing my own additional additives just cause I have it around.

I thought about steer manure, but then read about the high salt content (maybe for a brackish tank lol). 

I'm reading up to 9% carbon content in naturally occurring areas, and I'm thinking of using up to 10-20% With such a high proportion I would have to premarinade at least a portion of the "biochar" in a poo/pee/compost marinade to get them loaded up.


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## Fishly (Jan 8, 2010)

I'm not sure the manure from home depot is composted. Smell it before you use it. If it smells like manure, it isn't composted.


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## Knotyoureality (Aug 3, 2012)

Fishly said:


> I'm not sure the manure from home depot is composted. Smell it before you use it. If it smells like manure, it isn't composted.


They tend to carry both, though some of the stuff listed as "composted" is whiff enough that they obviously didn't do a thorough job on the process.


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## xenxes (Dec 22, 2011)

Fresh manure is much better for infusing carbon with nutrients, I read about 50% of its Nitrogen is highly soluable and is washed away with rain. 

In composted manure, the remainder is already converted to a stable form that releases the nutrients much more slowly. 

I'm going to try to get fresh or at least non-composted ones if I can to soak the charcoal in. Otherwise I'll just carefully soak it with some dog poo.


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## 691175002 (Apr 28, 2009)

The reason why most of us use aquasoil is because it comes in pellets which do not need to be capped and can be rearranged.

I'm curious as to what advantages you expect this mix to have over a standard mineralized soil tank.


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## xenxes (Dec 22, 2011)

691175002 said:


> The reason why most of us use aquasoil is because it comes in pellets which do not need to be capped and can be rearranged.
> 
> I'm curious as to what advantages you expect this mix to have over a standard mineralized soil tank.


Eh, much higher CEC from the carbon? Read above? The other stuff is just to customize pH and micronutrients.


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## lochaber (Jan 23, 2012)

I think some of the information in the Wikipedia article are a little misleading/unclear.

The "thousands of years" bit isn't referring to the soil's fertility, just that chunks of charcoal can hang out for that long.

It sounds like the charcoal acts pretty similar to anything else added to raise CEC, and is probably just a way to amend notoriously poor rainforest soils with methods/materials available. 

Anyways, not trying to discourage you, it's entirely worth experimenting with and such, I'm just not certain it will really help much more then say, safetsorb or kittylitter.


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## xenxes (Dec 22, 2011)

lochaber said:


> I think some of the information in the Wikipedia article are a little misleading/unclear.
> 
> The "thousands of years" bit isn't referring to the soil's fertility, just that chunks of charcoal can hang out for that long.
> 
> ...


The thousands of years bit includes continuous refuse being dumped into the river and broken down and absorbed by layers of charcoal. It will need to be replenished somehow over time, so would still need root tabs. 

Idk how much "more" effective this would be either, it's the latest fad in terrestrial gardening right now and people are making their own biochar (which is pretty extremey... roasting wood with your own barrel). 

Bottom line is it increases CEC / buffering. I think compared to safetsorb charcoal is better for microbial growth. Safetsorb is really like silica clay and not porous. Not sure about cat litter, probably depends on type, but any natural type like pine or saw dust or newspaper pellets would break down very fast. I'll post results over the next few months in the 90g


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## Monster Fish (Mar 15, 2011)

Cool. I'll be keeping track of your results. It's nice to see people experimenting with dirt substrates so people have something else to use other than MGOCPM in their tanks.


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## MassiveDynamic17 (Feb 3, 2015)

hmm 2014... Any progress? I recently came up with the idea of using terra preta, too... I was going to use it with an undergravel filter + powerhead. I had similar ideas about the recipe. A few other additive include marble. And worms are essential to condition the soil, methinks. And rooted plants.


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## Monster Fish (Mar 15, 2011)

MassiveDynamic17 said:


> hmm 2014... Any progress? I recently came up with the idea of using terra preta, too... I was going to use it with an undergravel filter + powerhead. I had similar ideas about the recipe. A few other additive include marble. And worms are essential to condition the soil, methinks. And rooted plants.


http://www.plantedtank.net/forums/1...ra-preta-dutch-jungle-shrimp-melting-pot.html

He hasn't updated since earlier this year.


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## roadmaster (Nov 5, 2009)

I have just re-dirted an 80 gal tank and first layer was a thin layer of plain topsoil with bit's of wood sifted out(hardly any).
I then sprinkled 1/2 cup of Osmocote Flower and vegetable pellet's on this thin layer of top soil.
I then sprinkled 1/2 cup of green sand soil amendment(iron,pottasium,magnesium + traces) and capped the afore mentioned with more top soil and product Safe-t-sorb.
Total depth of substrate is about five inches.(will settle some)
Waiting for plant's to arrive which will be a couple larger sword plant's,some crypt balansae,crypt becktii,crypt parva for foreground,and some water sprite to help fill in back ground .(tank is full ,filter's running)
Gob's of anubia from another tank to add also inserted among the smooth river stones.
Curious to see how long the substrate might produce for me compared to last soil/peat/cat litter mix which I got nearly two year's of good growth from.
Plan to re-do another tank in similar fashion using Azomite/soil/safe-t-sorb.
Tanks will receive water column dosing once a week as needed if needed.

P.S. I placed a couple colonized prefilter's in the tank and yesterday spied a lone cherry shrimp in the new tank that must have hitched a ride on the prefilter's +one snail #!&$!


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## Hilde (May 19, 2008)

xenxes said:


> Did some Googling on this and not much discussion, so I thought I'd start one!
> 
> Why buy expensive ADA Amazonia perfectly baked pellets when you can make your own?
> 
> ...


When I started I used *Cowboy* Hardwood Lump Charcoal and grew a few plants without Co2 which was told need Co2.

I thought Cow Manure was discouraged because of uric acid which will kill fish. Would you please clarify this?


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## micheljq (Oct 24, 2012)

I do not think charcoal would help about co2 if that is what someone is looking for. The carbon in there is locked, charcoal will not decompose and produce co2 in water.

Michel.


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