Adding Mbuna's

[zipperfly58]

I have 13 Mbuna's that I have moves from a 38 bow front to a 55 gallon tank. These fish were all introduced at the same time from the same tank in a LFS. My question is, I want to add more fish how many and what other types of Mbuna do you recommend. I have been told to ad in groups of 6-8 to lesson the aggression of the existing Fisk.

Stock list inclides
I male auratus
2 red zebra male &female
2 yellow labs not sure of sex
2 OB red zebra I know one for sure is female
1 Snow White
2 cobalt blue
1 blue zebra
2 red fin borleyi haps

Sizes range 3-4 inches

Thanks in advance