Can someone help identify this fish?

[cornflakes]

I added some small fish to my aquarium with red clawed crabs. I'm not sure if they are freshwater fish or brackish or both. RCC do best in brackish water so I was thinking of buying some aquarium salt to add into the water, but I want to make sure first if that's ok with these fish?

Here's a couple of photos.

Here's one of my crabs who enjoys climbing up the thermometer to sit on:

And another crab who likes to hide in the bushes ...i guess he feels safe there

 

[Angelbreeder]

Neon tetras

 

[Old Scales]

Those are Neon tetras. Paracheirodon innesi. You can look them up on Google and find out their requirements.

 

[cornflakes]

thanks to both!