# My Walstad tank is going wrong



## quatermass (Sep 27, 2006)

I put together a Walstad tank 2 months ago after reading her book and convincing myself it would work.

I bought a Interpet Aq3 cube tank which holds 60 Litres of water (40cm cubed) and has 2x compact fluorescent 15W lamps. they're on 10 hours a day.

I added a 1" layer of pond aquatic soil (I think it was marked as being sterile) and added a layer of dorset pea gravel around the plants.

I planted lots of Tropica plants which were labelled as 'Fast growth' and 'easy'. So mainly Echinodorus, Cryptos and a little Rotala rotundifolia.

The tank has a powerhead to push the water around.

As I was tearing down two small tanks to replace with this one I had to place the fish (Corys, Glow-lights and minnows) into it right away.

Using Stability it cycled in 9 days.

It all seemed to be going ok then I noticed my floating Riccia is dying, small quantity of duckweek floating on the surface is not growing and the Crypto leaves are getting cover with a light grey coating of what looks like filtering bacteria. Not the usual brown diatoms at all.
In fact I saw a Cory sitting on a leaf eating this loose scum off it today.

Overall growth has been slow and I'm getting small amounts of hair algae growing on the pwerhead outlet.

Some of the small anubias I put in from my old tanks is getting algae on it.

The tank seems to have generated a lot of suspended debris over the weeks.

Tank is kept at 25C

Tetra stick test:
NO3 25-50mg/l
NO2 0
GH 5d
KH 3d
ph 6.8

I did a 70% water change a week ago and added a tetra CO2 bottle (this feeds into a tube which I fill once a day).

I've taken some pictures of it:

click on pic to see big version.

Can someone give me some advice?


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## snowy (Jun 6, 2006)

Possibly reduce the photoperiod to 8 hours, that may help control the algae.

Do any bubbles come out of the substrate if you poke it with a skewer or a straw? If so, this may indicate excessive decomposition in the soil.

One thing you could try is to add a bunch or two of a really fast growing stem plant like Hygrophila. The swords and crypts are too slow growing in the early stages to be of any real use in sucking the ammonia / nitrate out of the water. Perhaps also try a different floating plant like Salvinia if the duckweed isn't doing well.

Sorry I can't offer more detailed advice but I'm sure there are others here who can help.


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## quatermass (Sep 27, 2006)

snowy said:


> Possibly reduce the photoperiod to 8 hours, that may help control the algae.


I'll do that.



snowy said:


> Do any bubbles come out of the substrate if you poke it with a skewer or a straw? If so, this may indicate excessive decomposition in the soil.


Yes. But surely this is normal for areas with no plants?



snowy said:


> One thing you could try is to add a bunch or two of a really fast growing stem plant like Hygrophila. The swords and crypts are too slow growing in the early stages to be of any real use in sucking the ammonia / nitrate out of the water. Perhaps also try a different floating plant like Salvinia if the duckweed isn't doing well.


I'd a good lump of Riccia in the tank. The duckweed was just a leftover from my old tanks. I was surprised to see the Riccia die off. I've never had any trouble growing this before.



snowy said:


> Sorry I can't offer more detailed advice but I'm sure there are others here who can help.


Thanks for your time.


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## bpimm (Jun 12, 2006)

quatermass said:


> I added a 1" layer of pond aquatic soil (I think it was marked as being sterile) and added a layer of dorset pea gravel around the plants.


Can you describe the soil? I looked at some pond soil and it looked more like the manufactured substrates for aquariums. You want a natural soil of some kind, not sterile. The bacteria in the soil takes care of the cycle. my 25 that I just set up never showed any measurable ammonia or nitrite buildup signifying a "cycle".

I think you may have built it with a non nutrient baring soil. The soil should look like dirt, smell like dirt and taste like dirt. Ahhh maybe scratch the taste like dirt. 

Brian


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## AaronT (Apr 26, 2004)

I agree that it was probably your soil choice. It's better to use the cheap topsoil they have at the garden center. Look for one that is free of fertilizers or any other added components.


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## whiskey (Oct 9, 2004)

One thing I see is a very short covering of pea gravel. I setup a 10G with very little rock over the soil and it was no end of trouble, I later setup the same exact tank with a full inch of soil and a full inch of gravel and it worked wonderfully.

Whiskey


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## Poochie (Nov 3, 2004)

If you are doing a Walstad tank..Why are you using CO2?


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## quatermass (Sep 27, 2006)

bpimm said:


> Can you describe the soil? I looked at some pond soil and it looked more like the manufactured substrates for aquariums. You want a natural soil of some kind, not sterile. The bacteria in the soil takes care of the cycle. my 25 that I just set up never showed any measurable ammonia or nitrite buildup signifying a "cycle".
> 
> I think you may have built it with a non nutrient baring soil. The soil should look like dirt, smell like dirt and taste like dirt. Ahhh maybe scratch the taste like dirt.
> Brian


The soil came in a bag and was labelled Aquatic Pond Soil and is a fine brown material and was in a lumpy condition when I got it.

I've got a bit left so I'll get the bag out of the garage tomorrow and re-examine the label.

It certainly looks like dirt.

Thanks Brian for the pointer. You could be right.


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## quatermass (Sep 27, 2006)

Poochie said:


> If you are doing a Walstad tank..Why are you using CO2?


Trying to save the tank plants? 

Today I added 50ml of ROWA Phosphate remover as I did a measurement and the phosphate is well over 5ppm.


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## quatermass (Sep 27, 2006)

whiskey said:


> One thing I see is a very short covering of pea gravel.
> Whiskey


Actually its deeper than it looks. The front has a covering of blue-green algae and the mulm is covering up the gravel. Look at the right edge.

I'm just wondering if I've been over feeding.
:noidea:


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## flagg (Nov 29, 2004)

The problem with your soil is that is was sterile. You DO NOT want sterile soil. Check out Walstad's chapter on substrate. Just to reiterate what bpimm mentioned, the benefit of using regular soil is that it contains all the beneficial bacteria a tank needs so there's no need for cycling. Using a sterile soil means that these bacteria are more than likely not present which makes the soil somewhat useless and could lead to the problems you are describing with excess nutrients.


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## quatermass (Sep 27, 2006)

I'm sure you're right. I'll recheck the packaging when I get home tonight.

Ok so my soil may have been sterile but surely it isn't now?
I've added lots of non-sterile things into the tank and it is cycled.

So what now?
Plants like the Riccia don't die off because the soil was sterile 8 weeks ago.
Surely the substrate and soil is covered with all sorts of bacteria now?


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## bpimm (Jun 12, 2006)

quatermass, 

Right now you have the possibility of several things working against you, your plants are not growing which could lead to anaerobic soil conditions. My suggestion would be to find a good soil and start over. it's not a very big tank so it shouldn't be too much trouble, I think it would be less problematic than trying to save the existing setup.

I use topsoil form my yard mixed with some compost with good results.

Brian


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## dwalstad (Apr 14, 2006)

Sorry to see this tank is not working out. The CO2 injection probably won't help. 

Be careful when setting up your tank. The water should start out crystal clear. If you've got a little turbidity, that means soil particles will settle on the plant leaves. This provides colonization sites for bacteria and algae on the leaves. Plants with coated leaves don't do well.

Making the gravel layer a little thicker would probably help. I recommend a 1 inch layer.


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## quatermass (Sep 27, 2006)

dwalstad said:


> Sorry to see this tank is not working out. The CO2 injection probably won't help.
> 
> Be careful when setting up your tank. The water should start out crystal clear. If you've got a little turbidity, that means soil particles will settle on the plant leaves. This provides colonization sites for bacteria and algae on the leaves. Plants with coated leaves don't do well.
> 
> Making the gravel layer a little thicker would probably help. I recommend a 1 inch layer.


Thanks Diana,
That makes sense.

I'll make the layer thicker.

I did a Iron test today and its zero.
So maybe its not a wash with 'an excess of nurtrients' and the plants are consuming it? The crypts are growing.

I have been feeding micro pellets (Hikari) for the small fish and perhaps these have settled on the Crypts and caused the coatings on the leafs?

I just assumed that the particles were caused by the mulm as in the first 3 weeks the water was crystal clear.

Many thanks for your input. :hug:


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## dwalstad (Apr 14, 2006)

If your Crypts are growing, that's a good sign. However, you need to get good growth of fast-growers. The picture shows the sword leaves smothered with algae. Not good. I hope you start seeing these fast-growers start producing new leaves. 

I'd like to see some floating plants in this tank for all the reasons I wrote in my book. Floating plants have major advantages over algae. For good measure, you could also add a few more submerged plants that aren't coated with algae.

While you didn't detect water iron, you could have plenty of other nutrients fueling algae/bacteria growth. Remember that iron, because it is so insoluble, may be absent from the water. Until you start measuring less nitrates and ammonia, I would assume that the water is nutrient-rich. The algae growing on the plant leaves may be feeding off of iron-rich soil particles that settled on the leaves. 

You only want to add CO2 when you've got healthy, fast-growing plants that can take advantage of it. Otherewise, CO2 will also stimulate algal growth.

This tank didn't get off to a good start, but I don't see it as hopeless.


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## medachef (Sep 21, 2006)

Thank you for also having the same problem as me and actually doing the same thing i did. I am actually going to break it down in the next couple days and increase the gravel to a constant 1 inch. I have wisteria and hornwort growing in the tank, but i think that i may be lighting it too much hence the algae. Plus when i first set up, the gravel wasn't as thick as it should be so i got a case of cloudy water, cleared quick, but still it put me on a bad foot to begin with. Sometimes i get a little hasty. and D. Walstad... i finally got your book in. it was worth the wait.


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## wiste (Feb 10, 2006)

> I'll recheck the packaging when I get home tonight.


I am curious about the contents of the aquatic pond soil. What is the brand of the soil?
While aquatic pond soil provides a media for plants to grow in it may be, depending on the brand, basically inert.
Aquatic pond soil would seem to be a better substitute for the gravel than a substitute for the soil.


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## Tentacles (Jun 25, 2006)

Reusing some of the water from the tanks you broke down to create this one, might have helped as well since it was probably well-cycled and it would be easier to set up the new cycle, a filter already in use in another tank would help too initially.

I found wiping the algae off the plants manually and doing a quick vac of that and the early soil detritous followed by a small top up helped enormously with keeping the algae in check.


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## quatermass (Sep 27, 2006)

wiste said:


> I am curious about the contents of the aquatic pond soil. What is the brand of the soil?
> While aquatic pond soil provides a media for plants to grow in it may be, depending on the brand, basically inert.
> Aquatic pond soil would seem to be a better substitute for the gravel than a substitute for the soil.


I've discovered that I've thrown the packaging out.

I had a look around the Garden centre yesterday. But they've not got the bags in stock (wrong time of year now I guess).

I'll try a internet search for it, but don't hold your breath. British products often don't have a web site for them...

I do remember it was called 'Aquatic Pond Soil'.

I've removed one of the Cyptos from the tank. it was growing enormous leafs!
I've added more floating Riccia. 
I've also cut down on the feeding. Its looking a little bit better.


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## jude_uc (Feb 7, 2006)

Out of curiosity, what did your dying Riccia look like? I've had a case where the Riccia got a small gray patch which spread to cover the whole mass. I've never been able to pin point why it happened... usually Riccia is quite happy to grow. 

-Adam


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## quatermass (Sep 27, 2006)

jude_uc said:


> Out of curiosity, what did your dying Riccia look like? I've had a case where the Riccia got a small gray patch which spread to cover the whole mass. I've never been able to pin point why it happened... usually Riccia is quite happy to grow.
> 
> -Adam


It got covered with a layer of what looks like denification bacteria and sank.


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