I would never suggest trying to "slow down" a fishes growth rate. Its not fair to the fish. Wouldnt you be pissed if someone starved a dog to keep it smaller? You can go without power feeding them, but Id still expect 1.5" to 2.5" a month for growth easily depending on the species. If you cant be sure youll be able to allow a fish to naturally grow like it should due to tank size then I highly recommend waiting on the fish. If its because you dont want one fish to outgrow another, I highly recommend waiting on the fish or setting up a second tank. I also would not mix africans with cichla. The water requirements are very different and even if it works your bass wont be very happy. Theres a reason you never see experienced aquarists mix africans with south americans. For tank mates, any kind of amazonian catfish, silver arowanas, flagtails are great and help clean up after them. Theyre not incredibly aggressive but can outcompete most other fish in the same water column for food.
