Do u have to switch to 12/12 or will it show wether its male or female once you keep on 18/6 for a while?
You are going to want to change the cycle to 12/12 and in about 6-10 days you will be able to determine the sex. Then revert back to either 24/0 or 18/6 whichever you prefer.
They will show sex under 18/6 after long enough veg time (60-90days) You don't need to flip 12/12 to show sex if you veg long enough.