need help dartfish?

[fishfish83]

i have a 73 gallon tank,i had purchased 2 dartfish 4 days ago, one is firefish, and other one is scissortail dartfish. today my firefish was hide in the live rock for whole day, and i am so worry about him. can anyone tell me what should i do? thank you!!!

 

[ophiura]

Will really be important to know the following:
Specific water parameters (ammonia, nitrite, nitrate, alk, pH and specific gravity) - even if "perfect" - allow yourself to get the pat on the back.
Age of tank
Other inhabitants