Mixing the African Cichlids with a Flowerhorn isn’t recommended. I thought Flowerhorns were a hybrid of South American Cichlids, which are fish that are from soft low ph water (correct me if I am wrong), so wouldn’t Flowerhorns do better in soft acidic water? I have one a Red Monkey I believe, from a guy a Flowerhornusa.com and I put him in my 300gal S/C American tank, was beat up for a couple days but now is healing and getting better. Also high grade Flowerhorns tend to very aggressive, so you African Cichlids would either end up getting killed or eaten by the Flowerhorn once it is large enough. It is also correct that African’s need a higher ph and hardness, they usually recommend high 7 to mid 8s.