Can I switch back to 18/6??

So I started an auto in the same tent I had a couple regulars in well after I started the regulars. The time came to flip to 12/12 and I just decided to let the auto go to that as well even though it was only a couple weeks old because I didn't have another tent. Now I have access to another tent and I'm wondering how much damage will I do if I move the auto back to a 18/6 schedule instead of the 12/12? It has only been in 12/12 for 2 days now...

Thanks so much

You'll be fine