I bought a few 1" from Petsmart, they are now 4"+, took more than 3 years to get to 4".
I think the question was if mbuna can be kept a) in a small tank when they are small and b) in a 40b when adults. I think that if you have awesome filtration (aquaponics/turf scrubber), or just a lot of good water changes ( a must for mbuna anyway), and plenty of line of sight breaks. A 40b is a 48" tank, which is what most people use for mbuna. The low water volume just means water quality will be more of a problem. Overstocking is the most popular strategy to keep your mbuna from killing each other anyway.
I have never actually owned one of these tanks, but my lfs has a 48" they have labelled as a a 40g. I guess it must have been a weird size. I assumed it was a 40B. You probably know better than I do.A 40 gallon breeder is not a 48" tank
I have never actually owned one of these tanks, but my lfs has a 48" they have labelled as a a 40g. I guess it must have been a weird size. I assumed it was a 40B. You probably know better than I do.