Hey Growmie,
Some people do try 24 hours light with autos but they use it for the whole grow cycle, not just germination. The average auto grower will use 18/6, it gives the plant time to rest and it saves on the electric bill. Feel free to shoot me a holler if you ever need any help, I'd be honored to assist you. Hopefully, this was helpful, and remember ... "Happy Growing" and "Free your mind one puff at a time".