while the rock is curing no water changes, it'll dilute the ammonia and nitrite making your cycle longer, its a phase the tank has to go through so let it. as soon as your test for zero amm. and nitrite do a 50% water change and then you should do 10-15% water changes a couple of tiems a month, some do them weekly, others biweekly. avoid large changes after the initial 50% because when you change that much water your more likely to have ph swings, temp swings and sg swings because of the new water.