[Blackheart]

So, I keep hearing everywhere recently how Cardinal tetras are supposed to be very hardy. Even better than their close cousins, the neons. But, I have heard in past videos that they are very sensitive also and neons aren't as sensitive.

So what's the truth here? I would believe that cardinals would be more finicky and sensitive due to being mostly wild caught? Neons I believe are not. Mostly tank bred. But, hell, I could be wrong.

 

[Discusluv]

Ive never had issues acclimating either neons or cardinals. Difficult acclimation is due to not paying attention to the water they are coming from to your own. Both in the short term-- TDS of source water and water acclimating into and long-term ( they need at least neutral to soft water.) In the short-term, if water composition is too different, these fish ( and many other soft-water characins) will die during acclimation. In the long-term, the desired water composition wont kill them, but the prolonged stress will lower immunity of fish and allow bacterial infections to take hold that they would normally-- if healthy-- be able to combat.

Now, disease is a different story. Cardinals, being primarily wild caught, are not prone to be carriers of the same diseases as neons that are primarily farm-raised. Not that the cardinals cannot catch these diseases if present in holding tanks or the hobbyists own. Conditions like Pleistophora hyphessobryconis, mycobacteria, and Flavobacterium columnare are rampant in neons becuase of the conditions they are raised in ( i.e cramped, recirculating systems). There are many diseases that can effect a neon that a wild fish is not exposed too. A cardinal or otherwise.

 

[Triport]

Pretty much my experience has been that all small tetras and barbs can be somewhat sensitive. You may have one time where 100% of the fish survive and you may have another time where not only do they all die but whatever they had wipes out half the fish in your aquarium.

So my recommendation is to always quarantine when buying cardinals (all fish but especially small sensitive ones). I have a few currently that are about 3 or 4 years old but I have also had them wipe out my entire tank at least 2 or 3 times in the past.