I have recently obtained several Jack Dempsay cichlids from a friend whose fish just had Fry. I have about 30 of them in a 130 gallon tank. I have sand as the substrate and about fifty pounds of lace rock inside for the fish to hide in. The largest of the fish is about an inch. I am filtering the tank with two emperor 400's using ammo-carb as the media. I am still having trouble keeping my ammonia, nitrite, and nitrate levels down. Do I have enough filtration? Are there any suggestions.