I bought a a group of 8 Neolamprologus Multifasciatus. I have had them for 9 days. They are close to if not adult size. When I got them they had 3 shells between the 8 of them so I bought them 36 shells. So they are in a 20L with 2 sponge filters in it with sand and 36 shells. The temp in the tank is between 78-80. The reason I'm concerned is that they are not eating much at all. I know they are small fish but when I feed them they don't even go after the food. I have seen a few of them come up and eat the food off the bottom about 20 min after I fed them. I have fed them Frozen Bloodworms, Frozen Brine Shrimp, Pellets and flakes. The other reason for concern is that they aren't digging at all. I read that they would re arrange their tank and they haven't done anything. So I was wondering if I am doing something wrong or if you all think they are ok. Let me know what you think.