First off what kind of cichlids do you have. Some grow very large as other remain relatively small. In a 75 ga tank, I would say it would be safe to place 2-3 females with your one male but make sure you can find females slightly larger than the male since he has already established that tank as his territory. Meaning-> he will attack the females into procreation whether or not they are ready for it. Not Good! Further more the changes of having a "ready to spawn" female increases with the size and age of this fish. NOW, if the fish would happen to pair of, they would eventually attack and kill the other fish in the tank unless they have adequate "hidding" spots. ie. caves, rocks, dense plant material, pots, anything where they can run to just in case they were going to get chased or bullied around. If not, I would suggest removing them or even bring the "non-productive" females to the store. Most places will gladly take a healthy fish back and give you a store credit, which you can use towards other fish or even food and different supplies and/or decor! Right now that's about all I can give you from personal experience and success I have had with certain cichlids(convicts, firemouths, & jaguar's). Now other types of fish(cichlids) require different conditions, which may or may not be different from the other 3 I have had success with. At this time I am trying to breed a (spelling check) hemiochromis laffalli(red jewels)
I was set back for 1 1/2 month because of an infection in my tank but now have it under control and will continue attempting until I succeed. Like Yoda said, "There is no try, either do or do not!" Soooo, let me know what type of fish you got and I'll see if I can find some more info on them and ask around 'till I find a reliable source that has successfully raised/bread them. 
