So I've been growing 3 plants that I thought were autos but now I'm convinced they are photos so I switched the lights to 18-6 and one is looking kinda yellow so I think she needs nutrients. Should I switch the lights to 12-12 because they have all been veging for atleast 6 weeks
It’s not inconceivable for a mix up of photo and autos. ILGM sells both for white widow.
If it’s been 7+ weeks, flip it to 12/12 and don’t look back.
Again, if you wanna play it safe, give it a week but after that, flip it
I would say to wait a week or two if you have the height. Some strains can take longer then others to flip. I can see one plant reverting back to photo but 3 plants would be rare from a reputable company.
Take a look at this grow. It was week 7-8 that they started to flower.
growdiaries.com/diaries/103495-grow-journal-by-roberts/week/565250
Once you start to run out of space( plant is half the height of your max light height(minus light to plant distance) Then consider flipping.
Two look much different.. I dunno man some autos can go 6ish weeks but much further it’s likely a photo. I’d just switch to 12/12 at this point.. you could wait another week or so just to be sure..