Hi this sounds great
I'm in the process of starting a Malawi tank but I'm not as ready for fish as you yet. The good news is that you have a great sized tank - is a 4x2x2 foot?
You are right in that the topic of mixing Mbuna and Peacocks and Haps is up for debate. For me I've decided to go down purely the Mbuna route for my 75 gallon and there are a few reasons for this. First is Mbuna are purely herbivores and Peacocks and Haps are omnivores but primarily carnivores. A lot of Peacocks and Haps actually eat young Mbuna. The risk with keeping them mixed is that the herbivores get too much protein which they can't process and end up blocked up leading to a condition called Malawi bloat, this can happen at any point in the fishes life so you could be raising a prize fish for 2-3 years and then they swell up and die. The opposite can be said for the Peacocks and Haps, if they don't get enough protein they don't grow properly.
Second factor is Mbuna are much more aggressive than Peacocks and Haps - the Mbuna live densely packed in rock faces and structures where as Peacocks and Haps are open water fish. This presents two problems, the Mbuna will attack other Mbuna and the victim knows the response is to hide in the rocks so they do but the open water fish just want to swim away which in a lake works but in a tank where do they go? The aggression and instincts issue also opens up a lot of issues when it comes to how to set up and scape the tank, if you put Peacocks and Haps in a tank with too much decor they don't have enough swimming room and also they will be more territorial with more decor in there - where as with more swimming room and less decor they are generally meant to be more chilled out. With Mbuna its the opposite, not enough rocks and caves = more aggression.
I decided to go with Mbuna over Peacocks as I feel its best to keep fish as naturally as possible and for these lake cichlids that is in mixed gender groups - the general advice I've had is to go for 1-2 males with 5-6 females though some species best as 1 male to 6-7 females with species that have a reputation of being a bit tough (though there are some species that I'm planning to stay well away from due to reputation like Auratus, Kenyi and Demasoni even though they are stunning!). My plan is to have 4 groups in my 75 and in a 120 I'd possibly do the same but with more females though you may be able to do a 5th if you choose in a certain way.
Within the Mbuna group its interesting that there are some species that are not true Mbuna and are considered more marginal species somewhere between a rock fish and an open water fish. This is things like Yellow and White Labs and also Acei species, the Labs do live in rocks but have a more omnivorous diet (though not as much as Peacocks) and Acei tend to live at the top of the rocks quite near the surface and are considered a borderline schooling fish, they are also a herbivore so fit well with 'true' Mbuna. I mention these as if you wanted to do a 5 species tank I'd do a group of labs, group of Acei and 3 'true' Mbunas.
The trick people say with an Mbuna tank is to keep species that look totally different. Eg one group of vertical stripes, one group of horizontal stripes, a solid yellow species, a solid blue species, a solid purple species etc - there are other groups and ways of looking at it but these are probably the main ones IMO.
From my research so far something like this would be almost 'easy mode'
5x White Labs (male and female sparkly white)
5x Acei (male and female blue body, yellow fins - few other options like the Ngara White Fin which is dark purple with white fins)
5x Rusties (male and female purple body, orange fins)
5x Saulosi (males blue and black vertical bars, females solid yellow/orange)
But there are loads more options and its quite endless when you start to learn the families and species.
By contrast if you wanted to go down the Peacock route, IMO even though its not 100% natural all male species is a good option. Female peacock cichlids are just silver or brown but the males are stunning, sometimes groups of males and females of one species can't mix with others, the males just get to aggressive so all male makes for a better solution but its not as natural for them... I'm on the fence if I'd want to do this route but this is the list I was working on for my 75g which when speaking to experienced people I got a good reaction to.
Peacocks -
Aulonocara Stuartgranti - Ngara Flametail
Aulonocara Rubescens - Ruby Red
Aulonocara Maulana - Bi-Color 500
Aulonocara sp. Stuartgranti "Maleri" Sunshine
Aulonocara Usisya
Aulonocara Turkis
Haps -
Copadichromis Trewavasae Mloto Likoma
Copadichromis Azureus
Otopharynx Tetrastigma or Otopharynx Lithobates Red Blaze
Protomelas Marginatus
Placidochromis Electra
You would have some other options though in a 120. One Hap species I can think of that would be worth devoting a tank to if you were into it would be Star Sapphires, one of the few hap species that is monomorphic between males and females and just a stunning, stunning fish - could be interesting?
I've stayed away from OB and hybrid species so far for Peacocks because they have a reputation of being unpredictable in a tank as you don't know what their genetics are but they do look good and if you wanted to try them with this list to get to say 15 adult fish it might be worth it. Interestingly by contrast, OB genes in Mbuna are totally natural and are a throwback in their DNA to an earlier stage of evolution - I'm quite early in my research on this side of things but using this kind of gene in an Mbuna tank gives some good options for some species females that are otherwise drab, but with OB genes you get some interesting patterns appearing.
One other issue with an all male Peacock and Hap tank is that I've found a lot of stores near me don't want to just sell you a single male as otherwise they just get left with a tank of grey females that few people want to buy but if you find somewhere that can sell single males great.
In terms of the fish you've got so far, if its not to harsh, I'd suggest taking them back and starting again. Decide if you want to do Mbuna or Peacocks and Haps and then buy your fish in much bigger groups, with the Mbuna get a group at a time and with the Peacocks and Haps get them in groups of 4-6. I've seen that if you add single fish to a Malawi tank it just gets battered as you are adding one fish to an established hierarchy, where as if you add 5-6 or more at a time it gets spread out and more likely to work.
In terms of how your current big tank is dealing with having Malawi fish in there, its quite a tough tank with the Nic's in there but long term its unlikely to work out. A lot of people keep Malawi species in mixed tanks and some people have 'success' but many many more have problems and deaths. Your Malawi will also need a real hard water set up with a hardness of 15gh + and a ph 7.5 and above, this level of alkalinity and calcium rich water will really influence how they grow and most of the other fish you mentioned will suffer in this kind of habitat.
Malawi can be quite daunting when you first start with them - I just avoided them 100% for the last 20 or so years of fish keeping but since I've started reading about them, its super interesting and the possibilities for colour and interesting behaviour is way beyond any other area of the hobby for me now. I've found its just a case of asking lots of questions and deciding where you are happy as there are a lot of different ways people keep Malawis, some I agree with and some I vehemently disagree with but can't deny that some people have a degree of success doing it.
This article is well worth a read
https://www.practicalfishkeeping.co.uk/features/the-mbuna-keepers-survival-guide/
And if you are into YouTube check out this channel
https://www.youtube.com/@CichlidBros they have some awesome Malawi tanks and go into a good level of detail, they've got Mbuna, Peacocks and Haps and also Predator Haps which is a whole other ball game (though not that different).
Sorry for the long post but I guess there is a lot to say when you are getting started
I've condensed a lot of research and reading that I've not found in one place here too so hope its not too much! And also one more final mention that I'm not keeping these fish yet so if anyone can see glaring errors or bad advice from me please tell me!
Wills
