The quality and quantity of the castings will depend on the quality and quantity of the food ect... whereas wigglers go through garbage/bedding at a good rate the Africans are tearing through the bedding and worm chow.
I add Glacial rock dust-bonemeal-eggshell-kelp meal by the TBSP to the bedding to improve the castings my worms make. Trying to find horse manure and a good source of screened topsoil to improve it even more.
Africans are TRUELY voracious! I have had wigglers for 2 years and they turn out castings, but no where near the rate that I am seeing right now with these guys after so little time. Should have done a pictorial of before and after, maybe with the next go round.