I wouldnt do it but theres no doubt in my mind itll work. Ive done some fd. up shit to plants. I think it would affect yield but a 60 day 24 cycle would be 50 days on a 20 hr cycle.
I've done 18/6 and 24/0 under HPS. I never noticed a difference in plant growth. Perhaps I just wasn't paying attention, or MH makes a bigger difference.
I just finished vegging today. I ran my clones for 24/0 for their first twenty-three days. I backed them off to the 18/6 for an additional seven days and now they are on their 12/12 light cycle. I felt better when I backed them off, just a personal thing. I know I can burn hard for a long time, but then I want a break. I think you do what you feel and keep an eye on them. It all works.
No problem minster. I personally wouldnt change them in the middle of veg. I think it would be better to switch them when there clones. Just in case. I dont think the 24 or 18 makes that much of a difference unless your veggin for awhile. I think you woul be fine switching but I dont have enough experience with that particular switch to say for sure.