newbie grower

i am in week 2 of veg and i've been running my light cycle for 24/0. i've been reading and some people say that this is harmful for the plant in the long run with soil issues and some deficiency problems could steam from 24 hours of light. Can i switch to 18 hour light 6 hour dark cycle now...

So i was casually starting a new collection had one of my lights lose alot of its leds so i removed it. And then added replaced light with same model light. I noticed i was getting white pistils, so i cut them all off hoping for a different growth and then i noticed my leaves changing texture...