# Topsoil vs. Potting Soil vs. Peat



## littleguy

I'm sure this question has been asked many times, but I wondering what the current thinking is with folks. I'm setting up a Walstad-style tank and am debating what soil to use. I am planning on using Eco-complete for the covering layer (not for it's "nutrients" but simply for its looks and texture). My water is soft but I'm hardening it with Ca, Mg, and bicarbonates. Here are my questions:

*1. Is there any effective difference between potting soil and peat for a natural planted tank?*

*2. Is there any advantage to using topsoil instead of potting soil? Instead of peat?*

I am leaning toward peat, since I already have a bunch and since I know it's "pure" - it doesn't contain chemicals, fertilizers, additives, etc. It also doesn't contain vermiculite and perlite, which are kind of annoying when they float to the surface. I am concerned about using topsoil, since our soil in central VA is basically just red clay.


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## sb483

Don't go with peat if you're setting up an el-natural tank. Diana recommends not adding peat to the substrate, since with its low pH it inhibits decomposition. Probably this is in the substrate chapter - if you haven't read the book you should take a look at it.


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## littleguy

Well, I guess that's what's a bit confusing about the book. On page 137 she says that in her experience potting soil has had fewer problems than garden soil in her tanks. But I believe potting soil is mostly just peat, sometimes mixed with bark and usually mixed with perlite/vermiculite. So it's not clear to me if there should be much difference between peat and potting soil.


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## sb483

It's the very low pH of peat that slows decomposition, which causes problems in Walstad-style aquariums (potting soil pH is low, but not as low as peat moss). She says this at least twice in her book - one is either in the substrate chapter or the last chapter, where she says something like "I wouldn't add peat to the substrate because its low pH can inhibit decomposition", and another is in a Q&A where a hobbyist noticed CO2 release from the soil (and thus all plant growth in the tank) had stopped and she remarked that low-pH peat in the substrate could be causing it.

Because she mentions it several times, my guess is it's not a good idea (however, I've never used peat so I have no practical experience with it).


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## AaronT

Top soil all the way. Potting soil contains added fertilizers and things like vermiculite that will forever float up to the top of your tank.

Peat can be used, but only as a first layer. This layer should be a very fine dusting that still allows you to see the bottom of the tank. It's main purpose is to promote bacterial growth in a newly setup tank. It's also effective at lowering the pH if put in the filter.


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## essabee

In an aquarium substrate I look for the following:-

1)	It should anchor the plants and add beauty to your aquarium.
2)	It should provide a bank of minerals available to the plants but not to the water column.
3)	It should remain friable and not pack up and become anaerobic.
4)	It should not leach chemicals or colors into the water column.
5)	It should not forever be changing your water chemistry by absorbing certain ions from your water column. 

Advising someone how to achieve it with materials which are variable is a disaster. Even doing it for yourself, will not forever hold the repeatability test. From various threads I have found that commercial substrate suffer from the malady that some batches do not conform to other batches. Hence the unending debates.

The only advice I am willing to give anyone is to avoid rich in Nitrogen soils.


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## Urkevitz

I setup a 10 gallon with potting soil 90% peat, with Soilmaster covering it. When can I expect to see problems??? So far things are fine, but it has only been a week.


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## Teeleton

I'm running sifted earthgro potting soil in mine. It was about $2 for a 40lb bag, and contains no added ferts, but it did have a lot of rocks, sticks and bark pieces that I sifted out.

Teeleton


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## Olvar

I've run two tanks with this style so far. The 10 gallon was a potting soil that didn't have added ferts, but was mostly peat 90% i think. That tank is currently a yellowish color, it started at two weeks and at four weeks now it is still like that. 

My 55 gallon has been set up for two weeks now. It is set up with very little of the previous potting soil added to a couple of bags of Hydoponex soil from Ace (only place i could find soil that didn't have tons of ferts here, it's mostly dirt and sand). So far that tank hasn't shown any signs of the water yellowing and the fish and plants in it seem quite happy.


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## cs_gardener

Potting soil around has either a lot of added fertilizer and vermiculite or has a lot of bark chunks and shreds. Therefore, I buy topsoil. It's inexpensive, doesn't have any additives and it works for me - what more could I ask for?


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## Robert Hudson

I don't think potting soil has peat usually, but maybe. There is not a whole lot of difference between potting soil and Top soil. They both have a lot of organic material from either compost or manure. Potting soil usually has perlite, (the white foam like beads) This is to aerate the soil to keep it from compacting and so that water will drain from it.... no use in the aquarium and it floats in water. Top soil often has perlite or vermiculite in it as well. Most bags of soil will list their ingridients. If you find a bag with a hole in it you can see if it has perlite in it or not.

90% peat in a substrate? Peat provides nothing really for plants. It contains no minerals and does not provide nitrogen. Some people use small amounts of it for the acid it releases as it decomposes. It also has good Cation Exchange Capacity, but large amounts of it may cause problems as it decomposes.

In the old days, it was more common to use nothing but peat as the substrate. I can't imagine doing that now


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## littleguy

Robert Hudson said:


> I don't think potting soil has peat usually, but maybe. There is not a whole lot of difference between potting soil and Top soil.


Actually, if you look on the back of most potting soils, the ingredients almost always list peat as the first ingredient. Sometimes they throw bark and "locally composted materials" in the mix too. Some people have had bad experiences with the "local materials" e.g. pine bark.

So to me,

(potting soil) - (fertilizer) - (vermiculite) - (perlite) - (local stuff) = (peat).

But maybe I'm mistaken. Does anyone know for sure?


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## DataGuru

here near Oklahoma City, I've had great luck with earthgrow topsoil from Home Depot.


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## littleguy

So far most who replied seems to favor topsoil.... Interesting. Does anyone here have personal experience with both topsoil and potting soil?

Does anyone have a good reason to choose potting soil?

And back to the other topic of this post, is there any real difference between potting soil and peat? By peat I mean stuff like this (looks almost exactly like potting soil):


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## dwalstad

essabee said:


> Advising someone how to achieve it with materials which are variable is a disaster. Even doing it for yourself, will not forever hold the repeatability test. From various threads I have found that commercial substrate suffer from the malady that some batches do not conform to other batches. Hence the unending debates.
> 
> The only advice I am willing to give anyone is to avoid rich in Nitrogen soils.


I liked Essabee's post.

That said, peat by itself is just dead plant remains including sphagnum moss; it is very acidic and almost 100% organic matter. It is not very nutritious for plants.

Potting soil is a mixture of many things designed to get good plant growth-- compost, peat, perlite, bark fines, sand, etc. It may be fertilized with iron and domomite lime, which is good. The dolomite lime will neutralize much of the peat's acidity and give plants needed calcium/magnesium. A small amount of iron fertilizer will definitely help, as peat is notably iron deficient.

I did advise against potting soils in softwater tanks, but now I realize that many potting soils are prepared with some added lime. Potting soils that have added lime would be quite suitable for softwater tanks.

Here's a link that gives you some idea of what may be in manufactured potting soils:

Indoor Plants - Soil Mixes

The above link indicates that potting soils may have nitrogen fertilizers (potassium nitrate, etc) added. However, nitrogen is not a permanent problem and can be dealt with. For example, bacteria will denitrify nitrates to nitrogen gas, and plants will take up toxic N compounds (ammonia, nitrite).

Potential downsides with potting soils won't last more than a few weeks or months:


You may have do some initial water changes and make sure that nitrites don't get too high.

You may have to add an airstone if the fish have trouble breathing- rapid organic matter decomposition may pull oxygen out of the water.

You may have to live with some water discoloration (yellow tinge) from released humic acids.


As a thin (1 " underlayer), I think many potting soils will work fine when combined with lots of plants, good lighting, etc.

If I set up another tank, it would be with potting soil.


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## littleguy

Diana, as always you are amazing :hail:



dwalstad said:


> If I set up another tank, it would be with potting soil.


So, what are the advantages (theoretically or practically) of potting soil over topsoil?


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## cs_gardener

Which potting soil and which topsoil? There is an endless variety of the two depending on where you live and what the stores carry. 

I find that their are more additives in potting soil that I don't want to deal with. In expensive potting soils there is vermiculite and perlite (both a nuisance to have floating) and fertilizer (which can cause major algae problems). Cheap potting soil in this area contains A LOT of shredded bark - about a third of the soil is made up of 1-3 inch long pieces that are great for drainage in a pot, but do nothing for an aquarium. I don't want to spend the time screening them out and they will float initially or gradually work their way through the capping substrate to make a mess on the floor of the tank. I'm about to redo my only tank with potting soil and use top soil instead. The topsoil I've found has a good texture (not too fine or coarse), has a decent mix of organics, and is currently doing well in a test tank (no water coloration, no algae breakout, nothing floating). 

What soil to use depends what you can find. The list of ingedients is helpful, but also look at the texture (find a bag with a hole). There are many variables that can make some soils more suitable than others for aquarium use.


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## littleguy

Great points too. 



cs_gardener said:


> Which potting soil and which topsoil? There is an endless variety of the two depending on where you live and what the stores carry.


Yes, so true. I admit I am vastly oversimplifying things by lumping substrates into a few categories. I guess I just want to hear what some of you experts are thinking before I make the plunge with a large display tank.


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## cs_gardener

Before you do a display tank, try a bottle test to make sure you won't end up with a lot of turbidity or massive algae problems. A couple of plant stems and a few snails will make the test more helpful as you'll be able to see how living things will do with the soil you chose.

I set up a spare 10 gal tank with my chosen soil and some spare plants about 2 weeks ago so I could see how it works before I redo my 30 gal. The results so far are very promising. I've added some shrimp and guppies to the 10 (and a sponge filter and heater) as its going so well. Kind of a back-handed way of setting up a new tank. 

You can use a canning jar or whatever is handy to see how your soil choice behaves. I sure wish I'd done that before I set up my 30 gal for the first time 2 years ago.


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## JPeeps

I'm in OKC and I use top-soil under gravel,picked up a 40lb from Lowes for I think $3.00. Took some time to pick out as much bark,stones,etc. as I could. Plants have anchored and grown very well. If only I could get water as rich in nutrients as my substrate.


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## littleguy

cs_gardener said:


> I set up a spare 10 gal tank with my chosen soil and some spare plants about 2 weeks ago so I could see how it works before I redo my 30 gal. The results so far are very promising. I've added some shrimp and guppies to the 10 (and a sponge filter and heater) as its going so well. Kind of a back-handed way of setting up a new tank.


Yeah, I'm seriously considering doing just that... Don't know how long I can keep a big empty tank in the middle of the living room before someone starts to complain... or I get impatient


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## essabee

cs_gardener said:


> Before you do a display tank, try a bottle test to make sure you won't end up with a lot of turbidity or massive algae problems. A couple of plant stems and a few snails will make the test more helpful as you'll be able to see how living things will do with the soil you chose.(snip)


That gets my vote! I used to use a 18"X15" aquarium for my tests of substrates.


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## Jimbo205

> I've added some shrimp and guppies to the 10 (and a sponge filter and heater) as its going so well.


 Catherine, may I ask how you did this?

I am asking the question because I am new :smile: (within 3-4 months) to shrimp and I have been afraid to add fish to my 2.5 Gallon and 10 Gallon tanks.

I am afraid to see them (multiplying (10 G) or not (2.5 G)) all gobbled up! :sad:


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## cs_gardener

Jimbo, I just bought a dozen ghost shrimp to see if they'd live ($0.30 each so its not a budget buster). I have a piece of driftwood with lace leaf java fern and java moss that no longer fit in another tank that I stuck in there and that provides a lot of hiding spaces. I've no idea whether the shrimp will survive long term or breed. I suppose the baby shrimp (if they ever have any) could be guppy food, but the adult shrimp are much too big for a guppy mouth (about half the size of a guppy?).

This is just an experiment for me, and its no great loss if the shrimp don't make it. I'll consider it a learning experiment. I've bought ghost shrimp before just to give my large fish (angelfish and gourami) some dinnertime adventure. Boy, did they ever have fun hunting the shrimp down! It would be great if I could produce my own supply of live food, but I'm not too worried if it doesn't work.

So anyway, research any fish that you're thinking of adding to make certain it won't worry your shrimp if not outright eat them. Make sure you've got plenty of hiding places for shrimp babies (java moss is great). Rethink adding any fish at all, a lot of people have strictly shrimp tanks and they look great! 

Oh wow, this is really off the topic of potting soil vs top soil. SORRY!!!


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## littleguy

*Thanks for all the helpful insight everyone!* It's nice that so many folks chimed in with their experience.

It's obvious there's no one "right" answer and there's so much variability in soils... even for identical brands... it was an oversimplified question to begin with.... So, I'm going to take the slow, patient approach:
Buy several different types of potting and garden soil at Lowe's
Bring them home, wet them and test their texture as Jane nicely describes here
Do bottle tests with the leading candidates
Maybe set up the 10 gallon in the study first, before setting up the 30 gallon show tank in the living room, just to be safe.
I have the time, and the bags are dirt cheap :mrgreen: so I might as well do things right.

Thanks again all.


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## Muirner

As Jane describes with soils, i have found Jolly Gardner topsoil. And by her result via pm i'll look into getting it. But being new to this whole FW planted deal, what does the jar test include? I know it's going to help see how the water stays in terms of clarity. but should i be testing in this time as well? Also what's the rule of thumb as far as how much you'll need in a tank?


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## onemyndseye

> If only I could get water as rich in nutrients as my substrate.


becarefull what you wish for! 

Excellent thread! .. My 0.2$ is use what you can collect from a natural source.... Then you know within reason that its chemical free and can sustain plant growth.....sift it through a old window screen  .... I recently used some soil dug out of the side of an enbankment that was almost tottally clay (greyish in texture) and mixed it with alittle of my "plain-ole-yard-dirt" .. that tank is doing excellent 

Muirner: For a bottle test... Take about 1" of soil and place it in the bottom of a old jar or bottle...covered by about 1" of gravel.... SLOWLY fill with water and let it stand for a week or 2.... over time you can test the water for Nitrates and Amonia, PH, etc.... so Youll have a good idea of how the soil will react to being submerged.... also youll be able to see if the soil clouds the water. or stains it... etc.

LOL.... or you could just do like me.... Jump right in 

Take Care,
-Justin
One Mynds Eye


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