funny acting chromis

[drakestraw]

i got two blue green chromises yesterday. the bigger of the two is acting fine but the smaller one is hanging out by the bottom of the tank in a corner. is he still aclimating or is he sick?

 

[drakestraw]

my chromis has moved away from the corner of the tank and is hiding under one of the rocks that creates a tunnel like area. he seems to want to get as far in there as possible. i have one clownfish( the other one died because i switched tanks from an 18 gallon to a 20 gallon)who is also hanging there. my clownfish died becuase of the toxic "waste" that was realesed from the sandbed during the tank switch and the clownfish( that didnt die) has been hanging out where the chromis is hanging out now could the 2 be related. just a reminder my bigger chromis is fine