You don't want to do so many big water changes that it messes with the tank's cycle. Cycling a tank is about developing the beneficial bacteria that process the ammonia out of the water. If you water-change it out, you're not building up those beneficial bacteria. I would just let it cycle. Keep it at a good temp, keep it running, put a fish or two in it and feed them so they poop (that's where the usual ammonia source is in a tank - fish poo and uneaten food). Let the bacteria that process that organic waste build up to where the levels aren't noticeable. Then add some more fish, maybe a really hardy coral or two.