Does Cardinals have lower tolerance for co2

[octopus]

Most of the hightech planted tanks that i came across is supplemented by the introduction of Cardinal/Neon Tetras. Yet i have this silly question. My personal experience has influenced me to ask this question.

I had about 40 Cardinals among other fishes in my 3ft tank. In order to boost plant growth the co2 was increased. On the very day it resulted in 2 dead cardinals. And before you know it over a period of 1mth since the co2 level was increased i am today left with only 3cardinals. Out of the 3 one of them has a distorted body profile. Btw i had the cardinals for about 2months without much of a problem before increasing CO2 level. Beside the cardinals 2 otos also MIA. The rest of the lifestocks are doing fine and feeding well. I tried introducing 2 newly purchased cardinals. Before i could blink my eye the 2 new cardinals were swimming vertically and grasping for health. Obviously they did not survive. On hindsight i should have introduced the new purchase to my tank when co2 is not activated yet. This would have given them time to acclimatise. But i did also throw in 2 newly purchased mollies 2 days before the cardinal without any tragedy.

The above incidents lends support to the assumption that cardinal has low tolerance for high co2 level. Hope i am wrong and there is some other hidden problem. Hope to get some answers.

[fendyf9]

How many bps yr co2 count?

[octopus]

How many bps yr co2 count?

countless. too fast. I depend on color of drop checker. Color is light green

[fendyf9]

I think u try to slow down to 2-3bps fr 1 week and try to see first..too much co2 cn kill most fish slowly..

[|squee|]

Don't depend on the drop checker too much, use your plant health / BBA as a more accurate indicator of adequate CO2.

Also try drip acclimatisation, and/or purchasing stock from a different LFS.