I have had as many as 7 chromis in my tank and, for a while, they swam in the open all around the upper 1/3 of the aquarium. A couple decided the grass was greener on the other side of the glass so jumped to their eventual death. The remaining 5 just hang out in a corner of the aquarium and never explore the aquarium any more except to come out and eat. All the other fish (anthias, tangs, hawkfish, rabbit fish, bannerfish) swim all over. I love the idea of a shoal of chromis but these five make me sometimes wish they would follow their former brethren into the abyss outside the glass. Anyone else have issues with reclusive chromis?