# Corydoras in Walstad tank?



## stefant (Jan 7, 2018)

Hi, I am considering setting up a 33 gallon (125 L) Walstad tank with sand and Corydoras (and other fish who like sand). But I wonder if it would work? From what I have read here, dwalstad recommends 2 cm of soil and 1 cm of sand on top if using sand not gravel. I have not kept Corydoras before, but would 1 cm of sand be enough or would they dig up the soil? Is it possible to safely use more than 1 cm of sand?


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## dwalstad (Apr 14, 2006)

I have no experience with Corys, so what I've written below is theory only. 

In my book, I recommended a sand depth of only 1 cm, because sand seals the soil layer--more than gravel--possibly making the soil go severely anaerobic. But if you've got fish digging up the sand, that will aerate the substrate. 

Bottom Line: I think you could make the sand layer deeper than 1 cm. Or you could start out with 1 cm. If the Corys stir the substrate up, you could just add more sand.


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## Maryland Guppy (Mar 5, 2015)

I have lots of Cory's, they only stir up about 1/4" of the substrate.
A really nice phish to have, they keep things stirred up and traveling to the filter.


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## DutchMuch (Apr 12, 2017)

Maryland Guppy said:


> phish to have,


=D> well done.
yes i got the pun.


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## Maryland Guppy (Mar 5, 2015)

Remember,I am Phishless!


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## stefant (Jan 7, 2018)

dwalstad said:


> I have no experience with Corys, so what I've written below is theory only.
> 
> In my book, I recommended a sand depth of only 1 cm, because sand seals the soil layer--more than gravel--possibly making the soil go severely anaerobic. But if you've got fish digging up the sand, that will aerate the substrate.
> 
> Bottom Line: I think you could make the sand layer deeper than 1 cm. Or you could start out with 1 cm. If the Corys stir the substrate up, you could just add more sand.


Thank you for your advice. I will make the sand layer a little deeper in order to have some margin.


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## stefant (Jan 7, 2018)

Maryland Guppy said:


> I have lots of Cory's, they only stir up about 1/4" of the substrate.
> A really nice phish to have, they keep things stirred up and traveling to the filter.


That,s good. I suppose it can vary between species how deep they stir up the substrate. What species of Corydoras do you have?


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## Maryland Guppy (Mar 5, 2015)

Panda and C-123


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## wojtek76 (May 15, 2018)

I keep Cory, Otocinclus and Malaysian trumpet snails. So far so good. They are cleaning very well excess food and prevent substrate be anaerobic. I also use eco-Complete substrate to cover soil that contains iron, calcium, magnesium, potassium etc.



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## stefant (Jan 7, 2018)

Maryland Guppy said:


> Panda and C-123


Thanks. These are both pretty small. I think I will go for _Corydoras panda_, since they are the easiest to find in a shop.


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## stefant (Jan 7, 2018)

wojtek76 said:


> I keep Cory, Otocinclus and Malaysian trumpet snails. So far so good. They are cleaning very well excess food and prevent substrate be anaerobic. I also use eco-Complete substrate to cover soil that contains iron, calcium, magnesium, potassium etc.
> 
> Sent from my iPhone using Tapatalk


Hi, what species of Cory do you have? For how long have you kept corys and Malaysian trumpet snails together?


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## wojtek76 (May 15, 2018)

stefant said:


> Hi, what species of Cory do you have? For how long have you kept corys and Malaysian trumpet snails together?


6 Cory Pygmmaeus
3 Cory Punctatus
About 4 months

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## stefant (Jan 7, 2018)

Are the Malaysian trumpet snails OK with the corys stirring up the substrate? Do they proliferate in your tank?


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## DutchMuch (Apr 12, 2017)

stefant said:


> Are the Malaysian trumpet snails OK with the corys stirring up the substrate? Do they proliferate in your tank?


yes and yes


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## wojtek76 (May 15, 2018)

Yes no problems 


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## wojtek76 (May 15, 2018)

I think Cory and Malaysian trumpets are good combination. Cory catfish stirring mulm and than mulm fall between gravel than trumpets snail mix deep with gravel.


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