Cardinal Tetra Mortality

[Colin_T]

For the OP

You can put Ammogon/ Zeolite in the bag with the fish. It removes the ammonia and then there is less chance of ammonia poisoning occurring. You can also test the water in the bag for ammonia. if there is ammonia, be careful about drip acclimatisation.

My guess is the main reason they are having problems is the massive change in pH. If you get more fish, try to get your pH to match the supplier's pH and see if it helps. You might have to set up a spare tank or use a plastic storage container for this, but it gives you time to slowly change the pH over weeks or months and will help to prevent stress from a sudden change in water chemistry.

 

[Byron]

@dasaltemelosguy as you are in California, cardinal tetras in local stores would probably be either wild caught or from SE Asia. In both cases, they are likely coming from very soft acidic water. The natural habitats are obviously thus, and so far as I know from a local fish store owner who gets her fish from SE Asia, they are raised in outdoor ponds and that is soft acidic water.

 

[Avel1896]

Paracheirodon "cardinal tetra" axelrodi is a soft acidic and black water fish.
• Ph should be 4 to 6.
• Hardness should be 6°GH maximum.
• Alcalinity should be 4°KH maximum.