Please Help With Aggression Issues In 50G

Hi All,
I recently added 8 new pets to my 50G.  The pets currently are as follows:
Kenyi: 2 Females/1 Male
Cobalt Blue Zebra: 2 females? 1 Currently Juvenile
Bumblebee: 1 sex undetermined/juvenile
Yellow Lab: 1 sex undetermined/juvenile
Mixed Mbuna: 1 sex undetermined/juvenile
Psued Acei: ? 2 Males/1 female
Red Zebra (Juggernaut!): 2 Female/1 Male (morphed-all same color!) Possibly 1 juvenile small male
Common Plec: 1
 
Hardware:
2 Aqueon Quiet Flow 55/75G HOB Filters; Top Fin Air2000; Aqueon 200w Heater;
 
Aqua scape:
African Cichlid Sand; White Coral; Assortment of Artificial Plants
 
Ok so the Acei, Red Zebras and Plec have been residents for eight months.  The others were added two weeks ago and I followed procedures offered to reduce aggression.  It was time for a major cleaning and redecorating so the current residents were removed, aquarium redecorated with added coral.  Some items were left in the set (i.e. Rock structure and Tree trunk) that the Male Kenyi took as residence.  The Male Kenyi solicited the desires of the female Red Zebra and were close to mating.  The male Red Zebra didn't take kindly to this.  Those two fought with the victor being the Red Zebra.  Now the Red Zebra male chases the two subordinate Red Zebra's back to the other side of the tank.  The aggression was great enough that I removed the rock structure and the tree trunk cause they were gathering points for aggression.  since I used all coral it has minimized some aggression but the kenyi still is keeping one side of the tank near the plants as his territory.  The female red zebra keeps going near him and doing a shimming type dance until the male red zebra chases her away and a standoff ensues between the Kenyi and the Male Red Zebra.
See pics below.  Your thoughts are greatly appreciated.  The tank is cycled and all other parameters are in check.
 
 
 
 

More breaks to line of sight will help. Adding in lots of caves and places to hide helps the fish by giving them plenty of places to retreat to.  Depending on how recently you put them in, they may just be sorting themselves out.  Cichlids are notoriously aggressive as I'm sure you know. So any new fish added in after you have an original set established will have to enter a trial period, generally. I have not experienced this lasting more than a couple weeks.  You may also have to face a hard truth, that some cichlids don't get along with each other.  Might want to consider a rehome if no luck getting them to cooperate. Best of luck hope everything comes out for the best.

I have a similar problem with 2 of my cobalt blue zebra's, they are so territorial towards the centre of my tank. I just put it down hierarchy (them being top) and to solve my problem i've just overstocked to spread the aggression. It seems to have worked as I never have any fish getting picked on or fin damaged

Thanks guys!  I increased the places to hide by adding more coral to increase height, length, and width.  It noticeably has helped as the aggression from the male Kenyi is limited to a 2 or 3 second chase and he throws in the towel.  Same with the male Zebra...he rarely has confrontation with the kenyi.  Thanks I appreciate the help!

Yeah, Mbuna are beautiful and interesting but also a major pain.
 
I don't think anybody has a truly 100% peaceful mbuna tank.
 
It only get worse as they grow and it's bad when you add new fish too.
 
Luckily, with plenty of hiding places and good water, they can prove to be hardy fish. But all the aggression doesn't come without a price, a lot of Mbuna, even in relatively peaceful tanks will be scarred for life and look war torn with various battle scars of long past battles.
 
It's just a fact of life I'm afraid...but yes, as others have said...retreats, rocks to break line of sites, overstocking and the right mix will all help.