Got a group of 6 Neolamprologus Calliurus from Qian Hu last year. They were almost adults when I picked them up and hence chose 2m and 4f from the store. The males were about 2" and females were about 1.5". Unfortunately, I lost one of them during transit and was left with 2M and 3F.
I made a new set up (24" x 24" x 16") for them with fine white gravel as the substrate. Introduced 6-7 large apple snail shells in the tank with cave formation in the center with few rocks. The shells were supposed to be for the females and males would hide in the caves. I had read that they were harem breeders.
After few days, each of the females occupied one of the shells and the males were on either side of the rock set up. Within 3 weeks they were all well set and one of the males started courting 2 of the females. I fed them Hikari Cichlid Gold Sinking (crushed) and made 40% water changes every 2-3 weeks.
To my surprise, with in 8 - 10 weeks, I had the first batch of fries. The fries were well guarded by the female with the male playing the supporting role. The rest of the colony didn't seem to bother the fries. However, after couple of days, I notice that other male had jumped out of the tank. I presume he was harassed by the breeding male. In the first batch, about 10 fries survived.
In the next 3 weeks, saw the fries emerging out of the shell of another female, which confirmed that they were indeed harem breeders. After couple of weeks, lost another female and the cause is not known. The male is about 2.75" and females are about 1.5". The two remaining females breed regularly and fries from both the females co-exist without any issues. I feed them Hikari First Bytes for the first 15-20 days and then crushed powder of the Hikari Cichlid Gold. I usually remove the fries when they are about 6-7mm in size and most of them seem to survive post that.