i have two big groups and they all get along and i am going to mix in a third . they wont cross bread if u get deffrent types , what size tank , and what u have in it they like rocks , and sand .tank no smaller then a 75 and group of one kind no smaller then 8
Everything is possible and I think there is a high possibility of them cross breeding. If you are not planing on selling the fry and are just going for the looks I personally would get them very small. 1.5"-2" so they'll grow up together.
There is only really 3 types of tropheus importing at this time. Sp. black, moorii, and brichardi. At least this is how we were learnt to keep which together with what.
The dubosi and ikola was considered as sp. black last time I checked.
Given the chance, they will crossbreed. But if you keep a group of each type, chance of crossbreeding will be much lower. But if you just want keeping a large number of them together and don't care much about breeding, you can mix and match.
Tropheus are no different than mbuna in the respect that given the right set of circumstances all males have the potential to cross breed with ripe females. The closer the tropheus are related, the greater the chance of cross breeding taking place. No respectable tropheus breeder will mix variants or species in the same tank for just that reason, and certainly not 5 different species.
As Charles has stated if breeding is not your goal, you can mix & match to your hearts content. Personally I think a large group of the same species makes for a much more dramatic looking set up, but that's just me.