Just to clarify for Veronica. Her tank has been cycled and is over 6 weeks old according to her first post. ;)

I would just ask the pet store what they were feeding their Hatchet tetras. Sometimes, they just need to get used to the "new" food. I doubt that the light is the problem. One last thing, make sure you have your top covered. Hatchet fish are known to jump once they are back swimming near the top.

__________________

--->Pictures of my 75g Amazon tank<----