Random fish death.

[Goop]

I have a 5.5 gallon tank fully cycled and lightly planted. I had 5 neon tetras and a Nerite snail. I checked the water quality of my tank this morning to make sure I could get 3 more neon tetras, but when I came home from the store I found one fish dead and another gasping for air.
My water quality is completely normal 0 nitrate, 0 nitrites, 0 chlorine, 7.2 ph.
I have three bagged neon tetras right now and I am worried about putting them in the tank, but I can’t return them back to the store since it is closed. What do I do?

 

[V227]

Might be a good idea to change half the water, even though it tests out okay, then acclimate the new Neons. I've read posts here on AA by very experienced fish keepers, losing Neon Tetras, sometimes a lot of them, even though water parameters were fine.
Might have been a bad batch of Neons, or a pre-existing illness, in particular Neon Tetra disease.

 

[Angellove78]

I have a 5.5 gallon tank fully cycled and lightly planted. I had 5 neon tetras and a Nerite snail. I checked the water quality of my tank this morning to make sure I could get 3 more neon tetras, but when I came home from the store I found one fish dead and another gasping for air.
My water quality is completely normal 0 nitrate, 0 nitrites, 0 chlorine, 7.2 ph.
I have three bagged neon tetras right now and I am worried about putting them in the tank, but I can’t return them back to the store since it is closed. What do I do?

Tanks not cycled. No nitrate= no cycle.

 

[Brookster123]

How's old the tank? Tanks to small for neons anyways. Betta or shrimp tank. Next to impossible to maintain steady parameters for desirable stocking.

 

[Goop]

How's old the tank? Tanks to small for neons anyways. Betta or shrimp tank. Next to impossible to maintain steady parameters for desirable stocking.

The tank is about 4 months old. Definitely a transition tank while I cycle a new 10 gallon. Will be moving my betta into this tank soon.

 

[Goop]

Might be a good idea to change half the water, even though it tests out okay, then acclimate the new Neons. I've read posts here on AA by very experienced fish keepers, losing Neon Tetras, sometimes a lot of them, even though water parameters were fine.

Might have been a bad batch of Neons, or a pre-existing illness, in particular Neon Tetra disease.

I did exactly as you said. I was iffy about my batch of neons to begin with. They always seemed a little less active than expected. I quarantined another questionable one just to be safe and will see how he’s doing when I get home.