Having an issue with my salt and pepper Corys .

[Richee]

This is much too warm. Provide the sources for anyone saying 79, I have this info from Ian Fuller and no one knows more about cories. I will say here that things like this are not in themselves the issue, but they weaken the fish making them susceptible to other issues. And nitrates at 20ppm is too high, if that is what they are.

The dirt under the sand is a problem. Such substrates cause issues with water quality until they are settled (about six months), and cories should never be over such things as they like to dig. There are bacterial issues with dirt.

I was going off of the walsted method , and father fish , not sure if you’re are familiar with those methods.

They say that the organisms that are in the dirt are beneficial and are more likely to find something harmful in your clean tank than anything from outside you get from a stream and put it into your tank. The fish live in the wild over dirt and sand anyways
, he’s got tanks over 20 years old that he’s never done a water change too and everything is thriving
Now the Cory temps could be wrong but everything I’ve read says 79 is the max

Salt and Pepper Pygmy Cory Catfish (Corydoras habrosus)

The Salt and Pepper Pygmy Cory Catfish is a very popular and active nano fish that is not often available. We are glad to offer tank-raised specimens!

aquaticarts.com

 

[Byron]

First, Walstaf has nothing about temperature for cories, and I disagree with her on dirt. She makes a statement in her book (which I have and like) about "plants cannot grow in inert substrates" which is just false. Her scientific sources for most everythiong else is well worth having, but soil is not a good idea especially with cories.

"Father Fish" I've no idea, but I can bet he has far less knowledge of cories that Ian who has spent much of the latter 50 years collecting and spawning them. Ian runs CorydorasWorld web site and has authored books. Forgt what the link says.

I just noticed reading back that ammonia is not given...this is a major issue with soil, and may be part if not all of the problem.

 

[Richee]

This is much too warm. Provide the sources for anyone saying 79, I have this info from Ian Fuller and no one knows more about cories. I will say here that things like this are not in themselves the issue, but they weaken the fish making them susceptible to other issues. And nitrates at 20ppm is too high, if that is what they are.

The dirt under the sand is a problem. Such substrates cause issues with water quality until they are settled (about six months), and cories should never be over such things as they like to dig. There are bacterial issues with dirt.

But I’m not sure if the temp would

First, Walstaf has nothing about temperature for cories, and I disagree with her on dirt. She makes a statement in her book (which I have and like) about "plants cannot grow in inert substrates" which is just false. Her scientific sources for most everythiong else is well worth having, but soil is not a good idea especially with cories.

"Father Fish" I've no idea, but I can bet he has far less knowledge of cories that Ian who has spent much of the latter 50 years collecting and spawning them. Ian runs CorydorasWorld web site and has authored books. Forgt what the link says.

I just noticed reading back that ammonia is not given...this is a major issue with soil, and may be part if not all of the problem.

the soil I have is pretty much sand , it’s very fine clay based dirt , I know the issues with iron already , and at least 2 inches of sand on top, the digging the Cory’s are doing barely goes below the surface , and everything else is thriving fine , I’m even getting breading behaviors from the pork chops and I haven’t lost 1 shrimp or any of the phoenix rasbora , this problem is coming out of no where I can’t see any problems with the parameters except maybe the temperature , it’s just all of a sudden that I saw a porkchop on the filter and then found 2 Cory’s on the bottom ,

 

[Richee]

First, Walstaf has nothing about temperature for cories, and I disagree with her on dirt. She makes a statement in her book (which I have and like) about "plants cannot grow in inert substrates" which is just false. Her scientific sources for most everythiong else is well worth having, but soil is not a good idea especially with cories.

"Father Fish" I've no idea, but I can bet he has far less knowledge of cories that Ian who has spent much of the latter 50 years collecting and spawning them. Ian runs CorydorasWorld web site and has authored books. Forgt what the link says.

I just noticed reading back that ammonia is not given...this is a major issue with soil, and may be part if not all of the problem.

What am I supposed to do then, rip the tank apart and change substrate ?

 

[Byron]

You posted with fish dying, and I have raised several issues that can contribute.

Substrate is very important. With respect you do not understand how the substrate can affect fish; bacterial issues cannot be seen, they are there. Cories should be able to upend themselves by half, as that is how they feed. The ammonia may be the actual issue, but everything that is not to the species' liking can contribute by weakening the fish. Temperature is extremely important, as it governs the metabolic rate and even one or two degrees can be detrimental.

 

[Richee]

You posted with fish dying, and I have raised several issues that can contribute.

Substrate is very important. With respect you do not understand how the substrate can affect fish; bacterial issues cannot be seen, they are there. Cories should be able to upend themselves by half, as that is how they feed. The ammonia may be the actual issue, but everything that is not to the species' liking can contribute by weakening the fish. Temperature is extremely important, as it governs the metabolic rate and even one or two degrees can be detrimental.

What do you mean by upend themselves ?? , alright I am going to put a different heater in there that can go down to76 the one that’s in there is preset to 78 . I’ll also keep doing regular water changes , idk what else to do besides started over

 

[Essjay]

What do you mean by upend themselves ??

When feeding, cories can bury themselves in the substrate looking for food. Their bodies are vertical with only the end of the body and tail sticking out of the substrate.


As for temperature, it is best to keep fish at the middle of their range. The edges of the range are temps they can survive at for short periods.
Salt & pepper cories, Corydoras habrosus - 20 - 26 deg C/68 - 79 deg F on Seriously Fish; 22 - 26 C/72 - 79 F on Planet Catfish. So around 74 deg F is best.

Pork chop rasbora - are these Trigonostigma espei or T. hengeli? Doesn't really matter as both have the same requirements.
23 - 28 deg C/73 - 82 deg F. Around 77 deg F is best for these.

Phoenix rasbora, Boraras merah - 20 - 28 deg C/73 - 82 deg F. Around 77 deg F for these.

 

[Byron]

Photos of the fish would help as other members have more experience with disease. Also, I don't think you indicated the total number of fish (species and numbers of each) in the tank. I agree fully with @Essjay just so you know.

 

[Richee]

Photos of the fish would help as other members have more experience with disease. Also, I don't think you indicated the total number of fish (species and numbers of each) in the tank. I agree fully with @Essjay just so you know.

Will post photos soon

 

[Richee]

Photos of the fish would help as other members have more experience with disease. Also, I don't think you indicated the total number of fish (species and numbers of each) in the tank. I agree fully with @Essjay just so you know.

I will have to get a video uploaded of the Corys . It’s hard to see them in pictures but the pictures of the dead one is just one , and I am seeing a lot of red on its top side so it’s making me thing it has that Cory disease I’ve been reading about

 

[Byron]

I believe those are Corydoras habrosus, worth remember to use this name so everyone knows what we are talking about. I will tag @Colin_T and @GaryE .

 

[Richee]

I believe those are Corydoras habrosus, worth remember to use this name so everyone knows what we are talking about. I will tag @Colin_T and @GaryE .

yes those are it . I started with 6 and I believe I’m down to 2 in the past week and a half . I think it may be the temperature was too high at 79, I have is slowly coming down it’s at about 76-77’F right now . I will get a video of the remaining swimming uploaded here shortly. Also the rasbora that are swimming in the picture , I started with 10 and I’m down to 7 now , found one in the pre filter sponge and the other two are gone , the phoenix rasbora started with 10, all 10 are still there, they are in the back behind the stem plants by the filter they stay there a lot, here is a picture of one of the Cory’s .

 

[AJ356]

This is much too warm. Provide the sources for anyone saying 79, I have this info from Ian Fuller and no one knows more about cories. I will say here that things like this are not in themselves the issue, but they weaken the fish making them susceptible to other issues. And nitrates at 20ppm is too high, if that is what they are.

The dirt under the sand is a problem. Such substrates cause issues with water quality until they are settled (about six months), and cories should never be over such things as they like to dig. There are bacterial issues with dirt.

Nitrates at 20ppm is too high? Any supporting evidence for that? If there is, I would be interested. If you have time, or the source.

 

[AJ356]

Nitrates at 20 PPM is usually the high end limit for most fish

Sorry, but says who please?

 

[Byron]

Ammonia, nitrite and nitrate are all toxic to fish. The first two act much quicker than the third, but it is still something to keep as low as possible. There is increasing evidence that 20ppm is the upper limit. Cichlids are now believed to be more harmed by nitrates, responsible for hole in the head for example. The effect of nitrate is slowly weakening the fish. The fish usually dies of other issues, but nitrates contribute to these so they are the underlying problem.

This should not be surprising when one realizes that nitrates in tropical watercourses are so low as to basically be zero.