# Substrate for Corydoras?



## Leopardfire (Sep 23, 2012)

I have 4 albino cories in my 20 gallon long tank. I know cories do best in sand, so I got some black aquarium sand from petco. When I put it in, it raised the ph to over 9 and I lost half my fish. The other cories are barely alive and hardly eat or move. I am going to move them into a 5 gallon tub while I fix the ph.
What substrate should I get for the cories? I really don't want to risk getting sand again because there's a good chance it will mess with the ph. Also, pool filter sand only comes in white which would blend in with my cories and I really don't want to spend another $40+ on petstore sand only to have it fail again. Would cories be okay in black gravel? I know it can be hard on their barbels, but if it was smooth and pretty small, do you think it would work?


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## ChoclateBetta (Jul 22, 2012)

I doudt it was the sand. What are the other decorations. Any substrate without jagged edges that are smooth.


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## Leopardfire (Sep 23, 2012)

I know it seems unlikely that it was the sand because so many people use that brand without a problem. However, I put some in a bucket and over the course of 2 days, it raised the ph from 7.5 to 8 and I'm sure it would have gone higher if I left it longer. I rinsed out the sand and repeated the test again to make sure but the same thing happened so I'm positive it was the sand. Do you think it's possible I got a bad bag?


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## ChoclateBetta (Jul 22, 2012)

Maybe a different brand if you want you could use planted aquarium sand but cories need soft substate without sharp areas for their barbels.


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## ChoclateBetta (Jul 22, 2012)

http://www.theaquariumwiki.com/Cories


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## Tikibirds (May 26, 2011)

Mopani wood may help. I know it lowers the PH of my water so much that I had to add coral and a bunch of shells to get the PH into the neutral region. 

or you can try play sand. I got a 50 pound bag for like $7 from Toys r Us


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## Leopardfire (Sep 23, 2012)

> Mopani wood may help.


Thanks could I find this at petco or petsmart


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## registereduser (Jul 30, 2010)

Leopardfire said:


> Thanks could I find this at petco or petsmart


I buy mine at Petco. I also use gravel that is not too rough and my cories have all their barbels. ;-)


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## Leopardfire (Sep 23, 2012)

> I also use gravel that is not too rough and my cories have all their barbels.


What kind of gravel is it? Did you get it at Petco too? 
Also, do you think I should try using things like wood to lower my ph or should I just get rid of the sand altogether


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## registereduser (Jul 30, 2010)

Leopardfire said:


> What kind of gravel is it? Did you get it at Petco too?
> Also, do you think I should try using things like wood to lower my ph or should I just get rid of the sand altogether


My ph is between 8 and 9 and my fish are fine but all I have is bettas, cories and otos (and snails). I haven't check ph since adding the wood, I should do that right now........

OK it's still darker than the 7.6 color on the card.

The gravel I got at a LPS and you can tell by looking at it that it's real little smooth-ish rocks, not the rough colored gravel people usually get at the store. I also bought several bags of smooth little glass pebbles (like for flower arrangements) at a craft store and mixed those in. I will add on a photo of my fish where you can see the gravel kind of close up. The green and white ones are the glass:


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## ChoclateBetta (Jul 22, 2012)

I have 7.6 PH too.


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## Leopardfire (Sep 23, 2012)

The gravel looks really good. Do you think the regular colored gravel they normally sell is ok, or should I look for something smoother like the kind in the pic?


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## registereduser (Jul 30, 2010)

The color on colored gravel tends to chip off. Look for a natural gravel, I think my bag said "aquarium aggregates"? You can tell just by looking at the stuff in the bags that some are a better smoother quality than others.

If you want something more colorful look in Michael's or even Walmart for the tiny glass pebbles to mix in.


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## Leopardfire (Sep 23, 2012)

I want black, so do you know if that color tends to chip? Also, is there a cheaper place than petsmart to buy black gravel that will work for fish? The pet stores are a little expensive


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## Leopardfire (Sep 23, 2012)

Hey would this gravel work? I'm thinking about using it for the cories http://www.petsmart.com/product/index.jsp?productId=3262881&f=PAD%2FpsNotAvailInUS%2FNo


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## harleraven (Sep 4, 2012)

My cories are on rounded gravel, and they are doing just fine. The bright pinks and purples make it easier to spot the little guys, too.


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## registereduser (Jul 30, 2010)

this looks nice and smooth

I'm not sure if the color will chip off or not with this product.

Aquarium gravel is expensive but you only have to buy it once ;-)


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