# What's wrong with a sand-only substrate?



## banderbe (Oct 10, 2005)

My 29 gallon tank has a silica (blasting) sand substrate, and that's it. No eco-complete, or anything else.

I have tons of fanwort, anacharis, and amazonian sword planted, and they are doing fine with just 18w of light.

I realize that they'd probably grow faster with some sort of nutrient rich substrate, more lighting and CO2 injections, but they are living just fine in what I currently have.

This sort of seems to make sense. Low lighting places low nutrient demands on the plants since they are growing slower.

I'm concerned that if I upgrade my light to a 65w coralife that the plant's nutrient needs will go up and that they will die.

I think plants get nutrients from the fish waste and my tank is "over-stocked" at least in some people's opinions.

Also I add Kent Zoe freshwater vitamin once a week. Says it adds essential minerals and nutrients that are good for plants.

Well, let me know what you think..


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## medicineman (Sep 28, 2005)

I do have worthless substrate in terms of plant nutrition, which is river sand (naturally crushed pumice) and zeolite. But my substrate has a very good CEC quality. Whatever fert I put into the tank, the substrate would sucks in some concentration and keep it. Once the water collumn is consumed of all the nutrient, the fert which being held inside the substrate would be released. It kind of works in balacing concentration between substrate and water collumn.

The problem with sand, I think it does not have the beneficial quality as above. The problem is obvious that you have to supply everything from the water collumn at higher frequency and adding some substrate fertilization such as root tabs of all sorts. Try PMDD method if you run it the sand way, it is alot cheaper. Fertilization which includes macros N-P-K, trace elements and chelated iron.

A word on increased lighting : carefully balance the fertilization and add CO2 injection, or youll likely to run into algae.


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## malkore (Nov 3, 2003)

biggest thing is to not use super fine silica sand, because it compacts down. aside from possible hydrogen sulfide pockets, the compaction will kill plant roots.

coarser sand, like pool filter sand, works really well. It may not retain nutrients as well as eco complete, but it still lets the roots breathe. If you make your own root tabs like I do, then sandy substrates are easy and cheap to maintain.


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## banderbe (Oct 10, 2005)

malkore said:


> biggest thing is to not use super fine silica sand, because it compacts down. aside from possible hydrogen sulfide pockets, the compaction will kill plant roots.


Which plants? I'm just curious because it seems like the plants I have are hardy and don't need much of anything.

They are certainly not dying. They look the same as when I bought them.

How long does this root rot take?

Then again, maybe my sand isn't too fine. It's just standard blasting sand from home depot.

I think I will just buy a 65W light, and see what happens.

It seems like a lot of people new to this are getting the idea that you have to have all this special crap in your tank to have a successful planted tank.

I understand hobbyists like to take it to the max, and tweak their setups for max growth but for the rest of us, a few hardy plants and your basic aquarium light will do just fine.

Or maybe I'm wrong and my plants will start dying.


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## Rex Grigg (Dec 10, 2002)

Again we run into the problem of defining sand.


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## jgc (Jul 6, 2005)

I am using blasting sand. I definately am seeing quicker growth from plants that feed from the column rather than roots - but root feeders are still doing well.

That said, next tank I will probably use a different substrait.


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## Rex Grigg (Dec 10, 2002)

Ok. Here is a picture of what I consider to be a good grain size for sand.


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## medicineman (Sep 28, 2005)

yep... that is what I like to have. 1-3mm in size and rounded edge. Stay away from coarser sand with sharper edges.


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## Rex Grigg (Dec 10, 2002)

That product is not sold as sand. It's a very fine gravel. But it is about as fine as I would want to use in a planted tank. It's actually pretty lightweight but doesn't compact.


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## malkore (Nov 3, 2003)

I agree 100% that the pic Rex posted would be good for a planted tank's substrate. It looks very similar to what is sold as 'pool filter sand' in my region.

What is not good is what's sold as Playsand at ACE hardware...Old Castle is a brand name in fact. If you buy sand substrate that would make amazing sand castles...its entirely too fine and will compact.


To answer banderbe: all my plants had rotten roots about 1" into the substrate...crypt retrospiralis, hygrophilia, rotala indica, even anubias nana...


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## banderbe (Oct 10, 2005)

malkore said:


> I agree 100% that the pic Rex posted would be good for a planted tank's substrate. It looks very similar to what is sold as 'pool filter sand' in my region.
> 
> What is not good is what's sold as Playsand at ACE hardware...Old Castle is a brand name in fact. If you buy sand substrate that would make amazing sand castles...its entirely too fine and will compact.
> 
> ...


But how long, time-wise, were your plants planted before the rot set in? And what was the result? Will column feeding plants with root rot just break free of the substrate and float but continue to live?


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## jimjim (Nov 9, 2003)

*Sand as a substrate*

I've been using play sand from various places since the late 60's and have never had a problem with plant growth, health or compaction. Some of my tanks were up for several years at a time. I use the PMDD method now but I started out with diluted house plant food. Play sand will work as well as other substrates, but, as said above, heavy root feeders will run the ferts out if you dont keep up with feeding them(fish poop and water changes included). A long two week vacation will sometimes mean nursing swords and lotus for a few weeks, other than that you shouldnt have any problem with it...Jim (of course YMMv)

Rex, where can I get some of the gravel you're showing. I love the color for a small tank I'm setting up.


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## wob (Apr 21, 2005)

Rex Grigg said:


> Ok. Here is a picture of what I consider to be a good grain size for sand.


Hey Rex,
That image really helps. It is hard to visualize what the gravel/coarse sand looks like based on a '1mm-3mm' description. I wish I had seen it before I went and bought my coarse sand, since it's a bit finer than what is pictured here, but I'm sure it'll work out anyway.

You may want to put that in your guide too to help us n00bs. 

Thanks!
Robert


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## rain- (Mar 29, 2004)

Here in Finland most of us planted tank enthusiasts use fine sand blasting sand, grain size either 0,2-0,6 millimetres (I use this one) or 0,5-1,2 millimetres. And we use them with success. Bottom ferts are needed, of course, and the sand needs to be stirred from time to time, but all the plants grow just as nicely as with the substrates Americans and others use. 

I believe there isn't just one right answer when it comes to the grain size of the substrate, they all have their pros and cons. You just need to know what you are doing and why. I think the best thing about fine sand is that you don't need to vacuum it and it looks really pretty. Using mostly fine sand and then a bit of coarser sand on top of it makes the bottom look rather natural. At least I like it that way


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## Rex Grigg (Dec 10, 2002)

You should be able to find a substrate like that a Industrial supply house. That sand is very common here on the west coast.

The play sand we get out here is gray dust. Nasty stuff to even contemplate putting in a planted tank.

I have been trying to remember the grit size of that sand picture I posted but can't right now. I will however find out what it is and let every one know in the next day or so.


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## malkore (Nov 3, 2003)

Every one of my plants had problems, except the java ferns, since they obviously don't 'root' the same.
Hygrophila snapped at the substrate. healthy anubias bartari v. nana had roots that were wilted directly at the substrate entry point, and were disintegrated about .5" down.
Crypt retrospiralis was the same way, no root system spread out in the tank and it was rotting about 1" down.
Anachris - would float a week after replanting because it rotted at the substrate line, again .5" down.

And this was a 29gallon with 80 watts, and CO2 injection. meanwhile my 20gallon with 55w, CO2, but using tahitian moon sand looks amazing.

Both tanks had MTS, so it wasn't like I didn't try to prevent substrate compaction...honestly I worried more about hydrogen sulfide pockets than root rot.

And playsand isn't all created equal. As Rex says, his Home Depot type playsand is gray dust...mine was very much silica sand, super fine grit also, and was total crap. If you got it to work, great, but I'll never ever EVER recommend the stuff to anyone. There are other, much better ways to get a cheap, decent planted tank substrate (like Rex's photo)


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