They do but as the normal answer goes stability is better then chasing a particular number. If the water is soft and can't hold a decent ph the use of "cichlid gravel" could be implemented.jwd , what’s the pH of your water? Don’t African cichlids need a higher pH around 7.8? However, I haven’t really kept Africans so....all I know is Dads love African cichlids.
I agree withtwentyleagues that this might be an issue with the cichlids eating the plants.
+1