Why The Death?

Had a customer come into the store with a fish issue. 
Where he has this tank with a bunch of fish and all of them are doing fine....
Except his neon tetras.

He's bought them multiple times and they keep dying on him.
But none of the other fish are having any issues. 

So he wanted to know what he was doing wrong so that the neons kept dying.

*shrugs*

Honestly it's hard to know.

There are some tanks where you just can't keep certain fish alive and it's a complete mystery.

I know that Platys never last for long in my tank for example.

And Mollies seem to be quite the divisive fish around the valley as they do great in some tanks and keep dying in others. 

But these particular neons?

Hard to know for sure.

Like the dude mentioned he had Angelfish.
So the angelfish could be picking on the neons as neons are a source of food for angelfish when they're larger.

But it could be the tank size. The tank temperature, the type of water used, the amount of neons you have together in the tank, how long the lights are on.....or you know just the fish themselves decide they don't like that tank. 

It's hard to know.
So I suggested trying different fish. To see how they did. 
And if there's any more death...to just let the tank set for a week or so before trying again. Just to make sure nothing else is stressing out the tank as well. 

-Sarnic Dirchi