Second cardinal tetra died in less than a month :(

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elephantnose3334

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When I came home from school earlier today, I was greeted with this: a dead cardinal tetra floating near the filter. I don't know how or why they died. They are discoloured and the blue stripe is faded. I am not good with fish diseases, hopefully I will learn one day. This is the second fish death occurring in less than a month. 3 cardinal tetras remain (half of the tank population) and 5 silvertip tetras remain. Again my tank is a Petworx 41L tall tank which I had for a year. I will do a big water change tomorrow or on the weekend.
 

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Have you got a test kit to check the ammonia, nitrite nitrate and pH of the water?
If yes, run a set of tests and post the results in numbers so we can see if there's anything off.

I doubt it's water quality though due to the silvertips being ok. You might have a bad batch of cardinals. How long have you had them for?
 
Have you got a test kit to check the ammonia, nitrite nitrate and pH of the water?
If yes, run a set of tests and post the results in numbers so we can see if there's anything off.

I doubt it's water quality though due to the silvertips being ok. You might have a bad batch of cardinals. How long have you had them for?
A year. The silvertips are older than the cardinals because I got them first, then the cardinals. The parents won't let me have testing kits due to their beliefs that testing kits don't work.
 
You went a very long time feeding the tetras twice a day and not doing many regular water changes in a crowded tank. It's the idea of cause and effect - even if you are now doing regular maintenance, there will be after effects from the period of neglect.

I had silvertips in my teens, before the 'water change era' changed fish lifespans radically. Even with no changes, they lasted for 3 years. I regret having kept them that way, but things were done that way then and I didn't know enough to do better. Back then, we'd buy neons, but cardinals were considered too delicate. I'd expect silvertips to outlast cardinals.
 
You went a very long time feeding the tetras twice a day and not doing many regular water changes in a crowded tank. It's the idea of cause and effect - even if you are now doing regular maintenance, there will be after effects from the period of neglect.

I had silvertips in my teens, before the 'water change era' changed fish lifespans radically. Even with no changes, they lasted for 3 years. I regret having kept them that way, but things were done that way then and I didn't know enough to do better. Back then, we'd buy neons, but cardinals were considered too delicate. I'd expect silvertips to outlast cardinals.
Hmm... I know, I make mistakes all the time. I seem to do water changes every two weeks.
 
Hmm... I know, I make mistakes all the time. I seem to do water changes every two weeks.

Dead fish begin rotting immediately. That's why Gary said, and most of us, will do an immediate large water change when you find a dead fish. Both because the body will have been rotting in the tank and putting the living fish at risk, and especially when the cause of death is unknown, the best first aid for whatever is likely to have killed the fish you've been losing is to do a large water change and dilute out toxins.

Even more essential when you can't test the water, so you have no idea if there are high levels of ammonia, nitrite, or nitrate in the water, and you have a history of over feeding and not doing enough water changes.
 
Dead fish begin rotting immediately. That's why Gary said, and most of us, will do an immediate large water change when you find a dead fish. Both because the body will have been rotting in the tank and putting the living fish at risk, and especially when the cause of death is unknown, the best first aid for whatever is likely to have killed the fish you've been losing is to do a large water change and dilute out toxins.

Even more essential when you can't test the water, so you have no idea if there are high levels of ammonia, nitrite, or nitrate in the water, and you have a history of over feeding and not doing enough water changes.
I got the dead fish out of the tank immediately yesterday and planning to do a big water change tomorrow. I feed my tetras enough food for the groups ( a pinch or two) and try not to overfeed them.
 
I got the dead fish out of the tank immediately yesterday

Sure, but how long had it been dead before you found it?


Chances are that you don't exactly know, but it will have begun rotting (which produces ammonia, toxic to fish) immediately, so if it died overnight and you didn't find it until the next morning, that's still several hours of rotting, the fish eating the corpse and producing more ammonia, etc etc.
and planning to do a big water change tomorrow. I feed my tetras enough food for the groups ( a pinch or two) and try not to overfeed them.

Tomorrow means doing a water change more than two days after finding a dead fish. That's not immediate. So if rising ammonia levels kill a fish, the body rots for 12-24 hours before being removed, and fish are still being overfed, it doesn't take long for ammonia to rise to dangerous levels and begin killing off more fish.

Whole tanks can crash because of escalating things like this. Most people overfeed, you feed twice a day without fail, which is more than the fish need, and most of us overfeed even when trying not to, so sorry, but you know it's true that you feed too much, and don't water change often enough, or enough volume at a time.
 
Sure, but how long had it been dead before you found it?


Chances are that you don't exactly know, but it will have begun rotting (which produces ammonia, toxic to fish) immediately, so if it died overnight and you didn't find it until the next morning, that's still several hours of rotting, the fish eating the corpse and producing more ammonia, etc etc.


Tomorrow means doing a water change more than two days after finding a dead fish. That's not immediate. So if rising ammonia levels kill a fish, the body rots for 12-24 hours before being removed, and fish are still being overfed, it doesn't take long for ammonia to rise to dangerous levels and begin killing off more fish.

Whole tanks can crash because of escalating things like this. Most people overfeed, you feed twice a day without fail, which is more than the fish need, and most of us overfeed even when trying not to, so sorry, but you know it's true that you feed too much, and don't water change often enough, or enough volume at a time.
I know... The fish died before I came home from school on Thursday, probably in the afternoon. :( Did I make a big mistake over time? I am prone to making bad mistakes. I am going to clean the tank first thing tomorrow because I didn't do it on today because Dad was very busy at the time.
 
Sure, but how long had it been dead before you found it?


Chances are that you don't exactly know, but it will have begun rotting (which produces ammonia, toxic to fish) immediately, so if it died overnight and you didn't find it until the next morning, that's still several hours of rotting, the fish eating the corpse and producing more ammonia, etc etc.


Tomorrow means doing a water change more than two days after finding a dead fish. That's not immediate. So if rising ammonia levels kill a fish, the body rots for 12-24 hours before being removed, and fish are still being overfed, it doesn't take long for ammonia to rise to dangerous levels and begin killing off more fish.

Whole tanks can crash because of escalating things like this. Most people overfeed, you feed twice a day without fail, which is more than the fish need, and most of us overfeed even when trying not to, so sorry, but you know it's true that you feed too much, and don't water change often enough, or enough volume at a time.
@AdoraBelle Dearheart

I understand that bad things can happen in whole tanks if we overfeed them, which I try not to. My younger sister's tank is in a worse situation. It hasn't been clean for weeks and the water is cloudy.
 
My younger sister's tank is in a worse situation. It hasn't been clean for weeks and the water is cloudy.
:(

I know... The fish died before I came home from school on Thursday, probably in the afternoon. :( Did I make a big mistake over time? I am prone to making bad mistakes. I am going to clean the tank first thing tomorrow because I didn't do it on today because Dad was very busy at the time.

I'm not saying it to criticise you, or tell you you're making mistakes. I'm trying to explain why we do water changes, especially when you cannot test the water, and fish have died, and why waiting even a few days, especially in a tank that's overfed and doesn't get enough water changes, can lead to disaster.

Not to criticise you. But to try to help teach you, so you don't wind up losing more fish.

I'm being shorter and more blunt because I don't want to overwhelm you with waffling, and because we've all been over this with you in many threads. You keep wanting to get more and more tanks and fish, but still aren't maintaining your own tank without your dad doing it for you.
 
I don't think there are mistakes made here. There are things not being done, when you've read many people here giving good reasons why they should be done. A mistake is when you pour a water change onto your shoes. A choice is when you don't do water changes.
 
You're going to keep finding dead fish kiddo.

Imagine a kangaroo with a nasty disease hopped on into your bedroom and died on your bed while you were at school. And while you're at school that dead roo is leaking all sorts of disgusting things all over your pillows and bedding. What would you do when you got home and found it? Would you just get your dad to take it out into the yard and then happily get into your bed? Of course not. You'd have to open all the windows, change and sanitise (or even throw out) your bedding and mattress, scrub the floors etc

When you don't do water changes after finding a dead fish, you're basically making the rest of your fish sleep in that dead kangaroo bed 🤷‍♀️



No kangaroos were hurt in this imagined illustration...
 
Enough with the earbashing, she knows now.

Don't panic over this, it happens. In future if a fish dies you try to do a water change asap to dilute anything that might have contributed to its death. You are doing a water change on Saturday so just do it then.

If you can post some pictures of the remaining cardinal tetras and maybe the silvertips, I will check them for diseases.
 

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