Loss of color in bronze corydoras

[Celine]

Good morning,
I posted about a month ago about one of my bronze corydoras becoming a pale grey and not being as active as my other cories. Sadly, this corydoras passed away. Since a few days now, I have another corydoras showing the same symptoms.
I have measured my tank levels and they read:
pH: 8
NH3: 0
NO2: 0
NO3: 0
KH: 4
GH: 8
I am trying to find out if this issue is coming from the general hardness of my water.
Could you please send me some advice as I am not too sure what could be the source of my problem? Thank you!
Celine

 

[Fish4dawin]

Your GH is extremely low which is good for some corys but Corydoras aeneus prefer GH of around 40ppm+

Here's a link which you can use to see what parameters they like https://www.seriouslyfish.com/species/corydoras-aeneus/

If you are unsure about water compatibility with fish always check seriouslyfish. It's reliable and a lot of people on this forum use it.

 

[Colin_T]

The GH has nothing to do with this and is less than 150ppm and that is fine for all Corydoras.

Did you use salt with the other Cory?

 

[Celine]

The GH has nothing to do with this and is less than 150ppm and that is fine for all Corydoras.

Did you use salt with the other Cory?

Yes, I did but he only survived 4 days after that.

 

[Colin_T]

Pictures of these sick fish?

 

[Celine]

Pictures of these sick fish?

I have attached a picture of my fish. I do think he is unwell as he is not as lively as my other corydoras. However, I can not see anything wrong on his body. It is just his lay back attitude that worries me

 

[Fish4dawin]

I have attached a picture of my fish. I do think he is unwell as he is not as lively as my other corydoras. However, I can not see anything wrong on his body. It is just his lay back attitude that worries me

He doesn't seem to happy that's for sure. I don't know what's wrong with him tbh. Could be a variety of things really.

 

[Celine]

He doesn't seem to happy that's for sure. I don't know what's wrong with him tbh. Could be a variety of things really.

This is him next to another of my bronze corydoras. The difference in color is obvious there. He is still very active when feeding but does not move as much as my other corys

 

[mrsjoannh13]

I am not sure if this would be a cause, but the pH is a little high. You can bring it down with some peat in a filter bag. I have used Fluval peat granules in a mesh bag in my HOB filter and it works well.

What temperature are you keeping the tank at and what and how often are you feeding them?

Do you have a group of at least 6 of the same kind of cory? They like to be in a group with their own kind. It might be stressed?

 

[Celine]

I am not sure if this would be a cause, but the pH is a little high. You can bring it down with some peat in a filter bag. I have used Fluval peat granules in a mesh bag in my HOB filter and it works well.

What temperature are you keeping the tank at and what and how often are you feeding them?

Do you have a group of at least 6 of the same kind of cory? They like to be in a group with their own kind. It might be stressed?

The temperature is at 25 degrees Celsius and I feed them twice sometimes three times a day, usually, they have a morning feed around 10am and an afternoon feed at 4pm. I used to have 4 bronze corydoras and 1 Julii corydoras but I lost one of my bronze corydoras a couple of weeks ago (same issue as this one) so I decided to wait before added anymore as I would really like to get this issue sorted first. My plan was to have 8 in total but I only have 4 at the moment. Also, this tank contains 64L only.

 

[Colin_T]

It's definitely not normal and the head should not be grey. It looks like excess mucous, which can be from external parasites or something irritating the fish.

You can try salt or a broad spectrum medication but I am unsure what it is.
It's not fungus or bacterial but there is definitely something wrong.

 

[Celine]

It's definitely not normal and the head should not be grey. It looks like excess mucous, which can be from external parasites or something irritating the fish.

You can try salt or a broad spectrum medication but I am unsure what it is.
It's not fungus or bacterial but there is definitely something wrong.

Thank you Colin. I will try the salt and see if it improves. There is nothing I can see on the fish itself except the loss of colour. I have changed half of my aquarium water today too.

 

[Celine]

It's definitely not normal and the head should not be grey. It looks like excess mucous, which can be from external parasites or something irritating the fish.

You can try salt or a broad spectrum medication but I am unsure what it is.
It's not fungus or bacterial but there is definitely something wrong.

Sorry Colin, but do you know if aquarium salt would be good enough? I am attaching a picture of what I used with my previous fish. Thank you!

 

[Colin_T]

aquarium salt is rock salt and that is fine.

use 2 heaped tablespoons of salt for every 20 litres of water.
keep salt in there for 2 weeks.
if no improvement after a week, try a broad spectrum medication.

 

[itiwhetu]

What are the other fish in this tank. I also feel that the pH is rather high.