# Setting up a soil substrate - any tips/suggestions?



## pfd2005 (Jun 20, 2005)

I'm currently setting up a new 45g gallon planted tank and I'm planning to use a soil substrate. In previous tanks I've used gravel, which was pretty hopeless, and mixture of sand and Laterite, which is working much better. But in this new tank, I want use a more natural alternative.

Having read a few horror stories about people using soil dug from their back yard, I'm planning to use a proper aquatic compost instead. From what I've gleaned from a load of books, I should be using about an inch of compost, topped with a couple of inches of other inert substrate, like quartz gravel. Am I on the right track? I've also ordered a heating cable from my local store, but I've been told by someone on another forum that I might not need it with a soil subtrate - is this likely?

I've tested the compost I'm planning to use, by soaking it in RO water for a couple of days, then testing the water. Ammonia and Nitrite were both zero  but there was a significant (>50ppm) Nitrate reading, as well as about 0.5ppm phosphate. Now, I'm aware that this test doesn't really replicate how the soil will behave in an aquarium, but do these results sound like anything to worry about - or are they fairly typical?

Finally, if anyone's got any hints or suggestions on how I might make this aquarium a reality, please yell now


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## AaronT (Apr 26, 2004)

Okay, here's the recipe a friend of mine uses for his soil substrates. First off DO NOT put anything organic like compost into your tank or you will have headache after headache. 

List of Materials:

Empty clean plastic tub or bucket
Bag of the cheapest top soil the garden center has (not potting soil!)
Muriate of Potash
Chick Grit from feed store (pulverized granite)
Dolomite
Lump of red art clay

1. Put the bag of topsoil in the plastic container and fill it the rest of the way with water.
2. Swish the soil around to allow the water to get in between all of the soil and let it settle.
3. Let it sit a few days and then change the water in the container and replace it with new water remembering to again swish the soil around.
4. After another few days drain all of the water out and let the soil completely dry out.
5. After it has been dry a couple days then refill it with water yet again.
6. Keep this wet/dry cycle going for a few weeks and the soil should be completely mineralized by the bacteria therein. Now there are no organics in the soil and you are ready to setup your tank.

In a small jar take a little bit; say 1/4 lb. of the clay and mix it with water until it is emulsified. Add this solution to the mineralized soil and mix it in well. Then mix in some chick grit until the soil seems like it will hold shape relatively well. The reason for the chick grit is so that the substrate slope in the tank doens't flatten out over time.

Take a handful of both the Potash and the Dolomite and sprinkle it on the bottom of the tank. You should still be able to see much of the bottom glass after doing so. Now add about a 1/2"-1" layer of your soil concoction. Now cap that with a 2"-3" layer of whatever inert substrate you choose. Tahitian Moon sand looks nice, but you can use anything you like. 

There ya go. Happy Planting!


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## pfd2005 (Jun 20, 2005)

Very interesting recipe, grandmaster. The procedure for processing the topsoil makes a lot of sense.

However, I've done a bit more research on the bag of compost I've got, and it turns out it isn't really compost at all. It's actually a mixture of loam, peat, limestone and some added nutrients. Will now do an organics test on the residue and see what that turns up. I suspect it will be pretty low, but if it isn't, your friend's technique sounds like the best way to remedy it.

I've also found some info on a tank with exactly the same brand of aquatic 'compost' in it, and it looks pretty good to me:

http://www.aquabotanic.com/contest/showdetails.asp?TankNumber=30

Any thoughts on whether or not I should use the heating cable?


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## AaronT (Apr 26, 2004)

I've never used heating cables myself. The general concensus seems to be that it's a waste of money. I would have to agree. I've been grown very healthy plants in just flourite for over a year now. 

The ingredients in the aquatic compost you have worry me. The loam will float to the top of the tank and you will be forever picking it off the surface. The peat is organic for sure and does not match the nutrients found in topsoil. Lastly, the limestone is a soft stone and will leach hardness into the water column. I realize that the dolomite I suggested is limestone too, but it's a very negligle amount. It's hard to say how much is in your compost. 

I forgot to add that one way you can tell that the soil is fully mineralized is that it will no longer have a smell when the water is in the container.


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## MiamiAG (Jan 13, 2004)

I find that heating cables are not necessary. Do you live in an area where it get particularly cold?


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## pfd2005 (Jun 20, 2005)

Art_Giacosa said:


> Do you live in an area where it get particularly cold?


Compared to Miami, yes... But the house is heated thoughout the winter, so it never goes much below 20C.


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## pfd2005 (Jun 20, 2005)

Okay, spoken to a few more people, and I've now decided to ditch the heating cable. Substrate is now installed and I'm just waiting for some more plants to arrive at my lfs. Many thanks for the tips and info.


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## AaronT (Apr 26, 2004)

Which soil did you decide to use?


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## Sir_BlackhOle (Jan 25, 2004)

Get Diana Walstads book, "Ecology of the Planted Aquarium"

It has everything you could ever need on soil substrates, along with tons of other good info. One of the best books around IMO.


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## AaronT (Apr 26, 2004)

Diana's method works well if you don't go hightech with CO2 and intense lighting and such. The mineralized soil method works better in that situation. This is not to say one is better than the other, but merely to differentiate between the two.


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## pfd2005 (Jun 20, 2005)

I've settled with the J Arthur Bowers mix. It isn't perfect, but I think it will suffice. Thanks for the book tip


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