Why did my cory catfish die?
Yes, some people thought my tank was a little overstocked - but I’ve been looking after it so well!
- I have a 28 litre tank, filtered and heated to 26 degrees centigrade.
- I’ve had the tank for 1.5 months, and the fish for 1 month.
- I have about 8 plants in the tank (they have root fertiliser in the gravel and receive a drop of leaf fertiliser 2/3 days). I leave the light on for about 9 or 10 hours a day.
- I do weekly 30% water changes and add conditioner/purifier every time.
- My ammonia, nitrite and nitrate levels are all 0. My pH is 7.
- I have a Siamese fighting fish, 5 cardinal tetras, 5 rummynose tetras, 2 (originally 3) albino corydoras catfish and 2 otocincluses.
- I feed them 6/7 days. They seem so happy and healthy.
Except I found one catfish dead last night. It looked perfectly healthy, but was definitely dead.
What could have caused its death? Was it just a particularly weak little fish or…?
I can’t understand how any tank conditions could have contributed… although some people say my tank is heavily stocked, the reputable fishkeeper/seller who sold me them told me that he has had many successful tanks of the same size and stock.
Thanks in advance.
Thank you for your answers so far. What I don’t understand though, is what is “poor water quality” when my tests all indicate that water parameters are fine? And I know that my kit works because a few weeks ago it showed a little spike in my ammonia and nitrates, but that has now equilibrated. The kit was expensive, too, so I hope it works!!
Marcel
May 25, 2009 - 8:31 PM
Dee Leprachaun
May 28, 2009 | 6:04 PMhe didn’t die…HE COMMITTED *******!!!!
Tenacious J
May 29, 2009 | 3:26 PMBecause Stephen Tucker ate it.
Josh J
May 30, 2009 | 6:33 PMthere can be many reasons, one of the is that fish was simply silly, water stability wasn’t very good, overfed maybe, etc.
pleccy
June 1, 2009 | 3:38 AMI’m afraid your tank is overstocked, this will be causing poor water quality which is the most likely cause of the fishes death. You say that your water parameters are normal, in such a heavily stocked tank I would be inclined to test it with another test kit, as your original test kit could be giving a false reading.
Julia
June 1, 2009 | 6:36 AMIf your Nitrates are at 0 then you tank isn’t cycled. That being the case, it may have died of ammonia poisoning.
You need to buy a larger aquarium for the amount of fish you have. The size is rediculous and even with weekly water changers, there’s no way that it can support the bio-load of so many fish.
Cory Catfish need to be in groups of 4 or more in order to be healthy and less skitish. Oto’s need at least 3 of their own kind. You need one more Cardinal and one more Rumynose to make it even.
You should upgrade to a 20 gallon, if not evne larger as soon as possible.
Gary C
June 4, 2009 | 4:42 AMIf the fish was only in there a month, it still qualifies as a new fish. There may have been something wrong with it when you got it, and whatever it was took a month to kill it.
However, I must say that your tank is not a little overstocked, it is grossly overstocked. You had 16 fish in a 28-litre (about 7-gallon) aquarium. About one-quarter this number would be more appropriate. It does sound as though your water parameters are good, but still, fish that are so crowded are under constant stress, which compromises their immune systems. The “reputable fishkeeper” who sold them to you is full of rubbish. This kind of bad information is what makes so many people give up fishkeeping after a short time in the hobby.
BigNorsk
June 6, 2009 | 7:30 AMIt is possible your tests aren’t accurate. A zero nitrate is quite unusual, maybe your test kit just doesn’t read anything until 20 ppm or so, some don’t.
The age of and all zeros brings your tests a bit into question.
Have you ever shown anything other than zeros? If not, I’d take a sample to a fish store that will test it and see if it agrees with your readings, that’s probably a good idea anyway.
The other thing that is quite possible is that for whatever reason your fighting fish hammered the cory.
Other than that, it’s quite possible the cory had a parasitic problem or something. Many times fish die and we don’t know why for sure. They don’t live too many years and you just don’t know history and age of fish when you first set up.
It’s quite normal to loose some or even many at first, out of all those if you’ve only lost one, I would say that speaks pretty well for your fish store.
Unless others die, I wouldn’t worry too much, but I would take a water sample and have the fish store test it.
Marv