how fast do maingano grow?

[a.tetreault]

i have 7 maingano in my 75 gallon tank, they were the first real group of fish i added and they were all about an inch long, its been about two months or so since i have added them and they dont seem to be growing much, my red zebras were smaller then the maingano when i added them and have already outgrown them. do maingano normally grow this slow? all other fish seem to be growing normally.

 

[joel618]

Idk about maingano, I have 4 different types of mbuna. My ice blue zebras were put in last and have outgrown some others.

 

[a.tetreault]

im just worried that they may not be getting enough food or something haha