Can I put Corydora in my tank when I have a soil / dirt substrate?

[meezazee]

Hi all,

I'm considering putting some Corydoras in my 200 L community tank as there are currently no bottom dwelling fish in there, however I heard sand or finer substrates are best for them. Will they be ok with my aquasoil substrate at the bottom? Or will this be harmful to them when digging and swimming around? I would appreciate any help I can get on this

 

[PheonixKingZ]

What brand is the soil? Most “aquasoil” (I say it like that because there are a TON of different brands) pellets are to big for corydoras.

 

[meezazee]

What brand is the soil? Most “aquasoil” (I say it like that because there are a TON of different brands) pellets are to big for corydoras.

Thanks for the reply. The soil was ADA Amazonia II Black Aquasoil.

 

[WhistlingBadger]

I probably wouldn't use this with cories. Looks like the grain size is pretty large for them. You could try some of the non-digging, small loaches (like dwarf chain loaches or zebras) if you want some action on the bottom.

 

[meezazee]

Thanks so much for the advice. Will look into those

I probably wouldn't use this with cories. Looks like the grain size is pretty large for them. You could try some of the non-digging, small loaches (like dwarf chain loaches or zebras) if you want some action on the bottom.

 

[Uberhoust]

I have two cories in a tank with Tropica Aquarium soil. They were not well when I got them from a friend that is no longer keeping fish, eroded barbels, but they really haven't gotten better since, whereas all my other fish do well. I wouldn't recommend cories with aquarium soil, though that is based on one experience only.

 

[Byron]

I agree with others. Ian Fuller, who knows more about Corydoras than most anyone else, is against any sort of "plant" substrate, and from the experiences of many of us, it is sound reasoning. Smooth sand is the only substrate that should be in a cory tank, and the sand should be the only substrate, i.e., not as a "cap" over soil or something else, as cories filter feed and will dig down through the substrate.

 

[meezazee]

I agree with others. Ian Fuller, who knows more about Corydoras than most anyone else, is against any sort of "plant" substrate, and from the experiences of many of us, it is sound reasoning. Smooth sand is the only substrate that should be in a cory tank, and the sand should be the only substrate, i.e., not as a "cap" over soil or something else, as cories filter feed and will dig down through the substrate.

Hi Byron, Thank you so much for the detailed reply, I really appreciate all the help! Yep, gotcha. I'll save the Corydora idea for when i have a sand substrate tank in future.. I'm still really new to the hobby so appreciate all the advice i can get Cheers, Mia.

 

[meezazee]

I have two cories in a tank with Tropica Aquarium soil. They were not well when I got them from a friend that is no longer keeping fish, eroded barbels, but they really haven't gotten better since, whereas all my other fish do well. I wouldn't recommend cories with aquarium soil, though that is based on one experience only.

Ooooh okay, sorry to hear they arent doing well. Thanks for the reply, i really appreciate it and I will definitely take the advice on board! Best of luck

 

[Freddykruger]

I switched from some gravel to sand and my cory r having a lot more fun with sand the the gravel

 

[Uberhoust]

I agree with others. Ian Fuller, who knows more about Corydoras than most anyone else, is against any sort of "plant" substrate, and from the experiences of many of us, it is sound reasoning. Smooth sand is the only substrate that should be in a cory tank, and the sand should be the only substrate, i.e., not as a "cap" over soil or something else, as cories filter feed and will dig down through the substrate.

About 2 months ago I would have probably disagreed with the comment above, but now I find myself agreeing with it. About a year ago I switched one tank to aquarium soil, the plants did really well for a no CO2 tank, the fish did well, I liked that the pH and hardness of the water stayed low. It was all good. After a month of observation I switched all my tanks to soil, and all the tanks did really well, particularly the plants, but the fish did well too.

The fish are always producing waste and that waste is hard to remove from the soil. In addition the soil is slowly breaking down. The first aquarium I put the soil in was the first to start having issues, I now get touches of cyanobacteria, I don't remember having cyanobacteria when using gravel, or more recently sand. I do weekly cleaning and 40% minimum water changes, the last few water changes have been closer to 75%. Personally I feel the soil is best for the plants but maybe not so good for the fish.

I am now looking for inert rounded river sand, to replace the soil in my one tank. I will be comparing it with my other tanks over a few months this time. It seems to me that the soil being a organic/inorganic mix, needs to be replaced every so often. It is quite expensive so I will not be going that route. I would also not recommend florite sand, it is too abrasive for bottom dwellers.

TLDR: I would use sand if your focus is the fish.

PS the cories are slightly better but they had a lot damage to their mouths and barbels, and their fins were highly eroded, I probably should have euthanized them rather than try restore them.

 

[Byron]

Your observation in post #11 tally with mine, and the accepted "knowledge" of the hobby. It has been noted by several advocates of "soil" substrates that the benefit is in the first year, namely the CO2 and ammonia produced by the decomposition of organics in the soil. After roughly 12 months, these people tend to agree that any inert substrate such as sand will be as good--Diana Walstad even states this in some of her articles.

The problem with this initial production of ammonia and CO2 is the effect on the fish. Which is why so many of these people recommend a dry start, and no fish in the tank for six months. This allows the tank to stabilize. Given that thereafter you are really no better off plant-wise than with sand, it rather proves why this is more of a problem than benefit.

Flourite nearly killed my group of cories, and within just a couple days. When I saw bleeding mouths I removed them to a tank with play sand, and they fortunately recovered, and I still have them some 8-9 years later.

 

[PheonixKingZ]

Thanks for the reply. The soil was ADA Amazonia II Black Aquasoil.

In that cause, no, I wouldn’t use it.

 

[meezazee]

In that cause, no, I wouldn’t use it.

Thanks so much for the help

 

[meezazee]

About 2 months ago I would have probably disagreed with the comment above, but now I find myself agreeing with it. About a year ago I switched one tank to aquarium soil, the plants did really well for a no CO2 tank, the fish did well, I liked that the pH and hardness of the water stayed low. It was all good. After a month of observation I switched all my tanks to soil, and all the tanks did really well, particularly the plants, but the fish did well too.

The fish are always producing waste and that waste is hard to remove from the soil. In addition the soil is slowly breaking down. The first aquarium I put the soil in was the first to start having issues, I now get touches of cyanobacteria, I don't remember having cyanobacteria when using gravel, or more recently sand. I do weekly cleaning and 40% minimum water changes, the last few water changes have been closer to 75%. Personally I feel the soil is best for the plants but maybe not so good for the fish.

I am now looking for inert rounded river sand, to replace the soil in my one tank. I will be comparing it with my other tanks over a few months this time. It seems to me that the soil being a organic/inorganic mix, needs to be replaced every so often. It is quite expensive so I will not be going that route. I would also not recommend florite sand, it is too abrasive for bottom dwellers.

TLDR: I would use sand if your focus is the fish.

PS the cories are slightly better but they had a lot damage to their mouths and barbels, and their fins were highly eroded, I probably should have euthanized them rather than try restore them.

Thanks for all the information

I appreciate you taking the time to write it all out for me. I understand the point.

My only defence for choosing soil at the time was ignorance, and I guess I got overly excited about a planted tank and wasn't focusing too much on the fish. I will definitely consider all this with my next tank.