Cardinal tetra deaths

[richardh]

Does anyone else have problems keeping cardinal tetras? I've had 4 die on me in 3 days for no apparent reason. All levels ok: 0amm, 0trite, 5trate, ph7.2 steady. Tank 3 months old and cycled. Temp 25C.

It just doesn't make sense?? They are/were a school of 10 introduced 3-4 weeks ago. Only 6 left now! Other tank mates are otos, harlequin rasbora and Pygmy cory, so nothing I would expect that would attack them.

 

[spkehl]

Your PH is high for them. They like a pH between 4.6 and 6.2. Also from what I have read, cardinal tetras are wild caught. They are not tank bred. This makes them more sensitive to their environment.

I have had similar results. My water ph was 7.6.

 

[bruinsbro1997]

Your pH is not too high for them. I have kept cardinal tetras in 7.6 pH no problem. If there is nothing else to blame (try testing for nitrates again, just to be sure), I would say it's the LFS. Sometimes they get wild-caught cardinal tetras, which are super sensitive and are more delicate than those bred in captivity.

 

[richardh]

Thanks for the comments.

I did a 50% PWC 4 days ago when I lost the 1st fish. Nitrates at the time were just 5. Tested last night and they were <5, but not quite 0. All within safe levels.

I wanted neon tetras at the time, but my LFS didn't have any left and assured me that his cardinals were just as hardy as neons anyway! Hmmm....I was and certainly am sceptical.

Let's see how the remaining 6 get on...

 

[aqua_chem]

Whenever I see a nitrate reading of 5 or lower, I have to ask if you are aware that you have to shake the bejesus out of the nitrate test kits for them to work?

On a hardyness scale from 1 to 10, cardinals rank at about 6.5-7, IMO/E. They are a bit touchy, especially to nitrates. The pH bit is a bunch of malarkey. I have them in 7.6 or so and they absolutely GLOW in my tank.

 

[richardh]

Whenever I see a nitrate reading of 5 or lower, I have to ask if you are aware that you have to shake the bejesus out of the nitrate test kits for them to work?

On a hardyness scale from 1 to 10, cardinals rank at about 6.5-7, IMO/E. They are a bit touchy, especially to nitrates. The pH bit is a bunch of malarkey. I have them in 7.6 or so and they absolutely GLOW in my tank.

Yes, i bang the **** of the bottle and then shake for a good 30 secs, before adding the drops and shaking again for a minute.

I read they were hard to keep and should only be added to a well established tank.
My tank has only been running for a few months, and although cycled, might not be mature enough for their liking.

 

[richardh]

Just recalled something. The first fish to die had no tail fin. It had either rotted off or had been bitten off by something. It was still alive when i noticed it and just floating around, but still had gill movement. The other 3 had no signs of damage at all.

 

[ejaramillo01]

IMO it was just a bad batch from the store...