# The mother of all substrates ?



## henkt (Mar 15, 2007)

Hi

This is going to be quite a long post, hope you have the patience to read through !

I am busy mixing substrate for my 2 (about to be rebuilt) 55G tanks and would like to hear your views on the feasibility of this home-brew substrate, which I am hoping will prove to be the mother of all substrates ! The substrate will consist of 2 x inert materials and 4 different soils, covered by small pebbles. I am attaching a picture with 5 of the components illustrated.

I will sterilize all the various soil components prior to use (a few hours in the oven at 200+ deg F).

Other than the soils (more about this below), my mix will consist of:

1 part Pearlite, simply because I like the ability of this inert material to assist in preventing the soil from compacting and the fact that it does provide some "air space" in the substrate.

2 parts Vermiculite, for trace mineral and CEC capabilities. The Vermiculite/Pearlite mixture will form 1/8 of the final mixture.

Background to the soils: I have been lucky to get access to a nearby clay brick manufacturing facility, where bricks and tiles are made from a locally excavated laterite-type clay, which is quite high in mineral content. (The water run-off in the clay pit has an almost turquoise blue colour, usually a sign of high mineral content). The bricks contain only clay and water, and no chemicals are added prior to the baking process. Reject bricks and tiles that do not meet quality standards are processed through a crushing plant and the resulting gravels are sold to e.g. the building industry. Gravel sizes vary from a few millimeters to about 19mm and the gravels are sorted by size. These gravels and clays are what I plan to use as the basis for the substrate. I have numbered the items on the attached picture for easy reference:

1. Red/Gray clay, very fine texture, my source is a batch of clay that has been partially fired, but where something in the manufacturing process interrupted the full hardening of the clay. The pieces can be crushed with your fingers. (1/8 of mix).

2. Orange/Brown clay, sandy texture, this is the raw material mined from the clay pit. (1/8 of mix)

3. Crushed clay brick, about 3 - 5 mm in size. This is from bricks that have been rejected by QA, but they have been fired through the kilns. (1/8 of mix)

4. Crushed clay brick, also about 3 mm in size, but majority consists of a finer sandy textured particle (1 - 3 mm), this is also from bricks that have gove through the baking process. This will form the bulk of my soil substrate, and makes up half (4/8 ) of the mix.

I have tested the pH of the soil mixture (items 1 - 4 mixed in proportion, soaked in distilled water for 2 hours), and it has a pH of 7.2.

My tanks are fed by pressurized CO2, controlled by Sera Precision Seramic controllers, so I control pH and typically end up with a pH of 6.8 and kH of 6.

5. The substrate cover will be pebbles that are sold commercially as a "Diamond Pebble Mix", it's literally the pebbles left after river-based diamond mining have sifted through the substrate for diamonds, so these are nice and round and they vary in size from about 2 - 10 mm.

I know this a bit of an overkill, but I felt like a kid in a candy store with all these soils available and got as many variations as I could !

I would love to hear what you think of the proposed mix and would welcome any suggestions on possible improvements to this. Would any of you add a few handfulls of peat to this ?

Thanks in advance,
Henkt


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## henkt (Mar 15, 2007)

Bump she goes !

I would really appreciate any input !

Henkt


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## Glouglou (Feb 21, 2006)

*Ok...*



> I will sterilize all the various soil components prior to use (a few hours in the oven at 200+ deg F).


Be sure it's no chemicals contaminants.



> 1 part Pearlite, simply because I like the ability of this inert material to assist in preventing the soil from compacting and the fact that it does provide some "air space" in the substrate.
> 
> 2 parts Vermiculite, for trace mineral and CEC capabilities. The Vermiculite/Pearlite mixture will form 1/8 of the final mixture.


Well, here I don't think vermiculite will be my product of choice , Good CEC, very lightweight and for the trace elements I don't think the release will be significative. To add a balance blend of element you can used fritted element in sale in good garden spot or hydroponic places. (used in very small amount).
Look at this:
http://www.aqualandpetsplus.com/Plant,%20Vermiculite.htm

I think I will go only wit Perlite

to be continued....

Take a look at this...

http://home.infinet.net/teban/jamie.htm


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## henkt (Mar 15, 2007)

Hi Glouglou

Thanks for the reply !
I had a look at the links (some time ago already) and other than the vermiculite's tendency to float, I could find no negatives. I have in fact got some vermiculite in my old tank, but this was a very fine grade and I did not soak it enough prior to installation, so I had a royal time after that keeping the tank clean !

This time round, I got my hands on a coarse grade (pieces about 3 - 4 mm) and I have soaked it for more than a month, so it is now completely waterloggged and the vermiculite is at the bottom of the container with a "layer" of water on top. I am fairly certain that this will stay at the bottom, because I plan to put a good layer of pebble cover on top of the substrate mixture.

Any thoughts about the clay and ground brick mixtures ? I am more nervous about this, since I have always just used river sand, and this is completely new ground for me (sorry, I couldn't resist the pun ! ).

Peace and thanks again for your input, much appreciated.

Henkt


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## Kelley (Aug 27, 2006)

I would avoid the vermiculite and the perlite. These are so lightweight that they will float you every time you uproot any plants.


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## Glouglou (Feb 21, 2006)

Thanks, Kelley. Looking around, I can see that vermiculite and perlite have tendancy to float.
Vermiculite can be messy when you uproot. Perlite is white, not necesseraly a good color in any substrat (question of choice).

About Perlite and vermiculite 
http://www.perlitecanada.com/

How can we replace the quality of these without the inconvenients: somebody try pumice...

One think I like about vermiculite it's is kind of spongious, and will not scratch anything, and the color is somewhat natural, compare to perlite (I change my idea about perlite, do not like white specks)
Question: somebody have good things to say about Vermiculite?

I think, youre completly fired clay, just like Soilmaster and Turface, can replace perlite and vermiculite because their role is to keep soil to become compact, they have big CEC (especially Turface) they will not be as messy.

And if you want them at a smaller size for mix with lower layers you can crushed to your liked...



> 1. Red/Gray clay, very fine texture, my source is a batch of clay that has been partially fired, but where something in the manufacturing process interrupted the full hardening of the clay. The pieces can be crushed with your fingers. (1/8 of mix).


Well here I think you have deshydrated clay, it lost is chemically bond water (partially fired) This is a little bit like Laterite and probably have some similarity, low to medium CEC, and will leach some nutrient faster then the completly fired clay.

and



> 2. Orange/Brown clay, sandy texture, this is the raw material mined from the clay pit. (1/8 of mix)


I will use this for the bottom layer maybe mixed with the partially fired clay (crush somewhat finer than photo but bigger that the raw material (rough guess 30% number 2 raw material with 40% number 1 partially fired the rest with vermiculite or/and some of the crush brick to prevent compacting, good CEC and a little bit of peat or/and sphagnum to keep that layer acidic for iron avaibility and bacterial activity starter.

I will even trow in there some simple dirt (5%)
This will be a nutritive bottom substrat.

for the top layer go with more of the big size chunk, less of the other stuff (keep everything bigger... I think you better related on the CEC capacity of the top layer.

Maybe I make sense....:mrgreen:


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## Glouglou (Feb 21, 2006)

About the pretty turquoise water, that worry me a bit. Looking around I saw that turqoise water was sometime associate with very low organic count. Did you see something alive, moss, algae something?
ainkille


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## henkt (Mar 15, 2007)

Hi Glouglou

Thanks for your detailed answer ! rayer: 

The clay pit is actually in use, so the turquoise water is fairly fresh but quite deep inside the pit, so no, I couldn't really see any algae, etc. What I can tell you is that the pit is in a winelands area and it is surrounded by some of the most lush vineyards - the upper soil must have some excellent organic properties, although I doubt that the soil from deeper in the pit has much (if any).

My fish are all in one tank at the moment, so I have the ability to expirement in the (new) one without fish, before I break the fish tank up for rebuild. I will mix in the perlite and vermiculite, since that would only form about 15% of the bottom layer, and see how that works after a bit of planting and replanting. I will post pictures and updates as I go along.

I have some peat moss that I will add as organic matter, this is not as pure as your spaghnum moss, as it actually contains a bit of pine needles and bark as well, in order to generate the intitial bacterial start.

You make more sense than you know, thanks so much for this.


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## Glouglou (Feb 21, 2006)

Whatch out pine and other coniferous are known to contain poisonous crap.

You can buy peat granule from pet shop, fairly cheap and completly safe, for the quantity you need I will go on the safe side...


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## Robert Hudson (Feb 5, 2004)

Some years ago I knew someone who was gung ho for vermiculite. What he would do is put it in a bucket of water and kneed it like dough, forcing the air out and separating the gold flecks and discarding them. What was left would then sink in water, and according to him still provide a high CEC medium. Perlite and vermiculite are used in potting soils to prevent soil from compacting in a pot and to provide drainage.

I would not use any gravel in the top layer that is bigger than 2mm. The plants would have a hard time growing in it, particularly any ground cover type plants.

The main problem I see with your substrate is its all clay, and it will all turn to mud. The reason laterite and clay is used in very small amounts in the substrate is because you only need a small amount to provide the needed iron, and in excess it just becomes a pollutant. If you combine small amounts of some type of organic top soil or potting soil, you will also then have a substrate that provides NPK. Peat provides acid that helps keep minerals in solution and has decent CEC, but does not provide any minerals or NPK.


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## Glouglou (Feb 21, 2006)

Robert bring a good point here, beware of compacting soil.
It's for that reason that I will keep the half fired clay


> 1. Red/Gray clay, very fine texture, my source is a batch of clay that has been partially fired, but where something in the manufacturing process interrupted the full hardening of the clay. The pieces can be crushed with your fingers. (1/8 of mix).


 in the lower layer and mixed with the other well fired clay, ( have to be fired over 800 degrees to keep is shape, vermiculite ( anything to keep the soil to become a slab of hard clay and a small addition of peat in there will be beneficial to keep all that on the acid side and the ligand it release will keep the iron available.
But, if you keep this layer not to thick around 1 inch to 1 1/2 compaction will not become really a problem for the plants roots.

Keep the higher layer with a mix of well fired clay, here the CEC will draw nutrient from the water column and from the bottom layer.

For the medium layer find a mix of all these elements. (just keep it less compact than the bottom layer and more compact than the top.

The addition of pot soil in this is great because your substrate become complete in nutrients, more natural.

Go visit El Natural and snoop on their stuff :spy: , very interesting and I'm sured they don't mind.

Clay are often unbalance in nutrients by is nature of wash-out rock that loose or gain many elements in is transformation to clay.


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## henkt (Mar 15, 2007)

Thanks so much for all this fantastic information. I have started laying the substrate down today and have modified as per your suggestions as follows:
Bottom layer: Larger pieces of fired clay brick (about 10mm) mixed with smaller (2-5mm) fired clay brick - this to provide aeration and to prevent the mud slab from forming, into this I mixed some of the richer, raw No. 2 clay (which I have now established is the layer just below the top soil where it is mined) and a few handfulls of peat. The layer was bedded down by wetting it very slowly. I am not going to use the No. 1 clay, because an expirement with this fine powdery clay in a glass container showed exactly what Robert described, it sedimented down into an almost solid muddy clay layer that would have been anearobic in no time.
Middle layer: My "power mix" of Vermiculite, Perlite, some ADA type processed soil (DAZS) that I had handy, a very small amount of peat, and the No. 4 finely "Crushed Brick" which I have in the meantime established is actually a "scrape" from the crusher area and it is a mix of very finely ground brick and topsoil (this is actually sold on to nurseries). This layer looks fantastic and I am sure this is going to be the "power centre" of the substrate.
"Mezzanine layer": I added about 1 cm of the No. 4 mixture above the "power mix" just to make 100% sure that the potentially floatable pieces are contained... I am a belts and braces kind of guy...  
Top layer: I have sifted the Diamond Pebbles and have used only the fine pieces as a top cover - this looks absolutely stunning against the driftwood centre pieces (I'll post pictures soon).

Today I also invested in a pair of aquascaping tweezers, so I am confident that I will be able to insert and extract plants with surgical precision !

I will be filling the tank to about 1/3 level for the first plants that are going in, but I am trickling water into the tank through an air hose to make sure that there is little or no surface disturbance. I have come to realize that patience in this hobby is not only a virue, it is a requirement !!!

I am really excited about this tank (the first of 2 new layouts) and I am trying a variety of new things like terracing, so I am taking lots of pictures and will pick a few choice ones to post in the days and weeks going forward.

Once again, thank you for your generous input - this is undoubtedly the premier Aquatic Plant forum on the net !

Regards,
Henkt


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