tetras

[Lupin]

Nix the neons (they aren't hardy like they used to be)

It just depends on the source where you got them.

and get some cardinals instead. Look almost the same, slightly bigger, a "better" blue in my opinion, and they are more hardy than the neons.

The only disadvantage is that they are more expensive than the neons but are well worth it. Most are still wild-caught and these ones are trickier to keep than the captive-bred ones.