Looking for Advice; When to Start Flower

[OGHomefry]

Hey Everyone,

I'm wondering when I should start flowering. I have six plants in a RDWC. The tallest one (White Widow) is from seed and pretty bushed out and is currently about 2 feet tall. There is another White Widow from seed that's about 1.5 feet and pretty bushy. The others are clones and stand about 1.5 feet tall (about 4-6 weeks old). Ideally, I was hoping to let the clones and shorter White Widow grow for another few weeks and catch up to the bigger plant but I'm worried about having enough vertical room. My tent is 6.67 feet tall. My question for all you experienced growers is when would you start flowering?
My secondary question is what's causing the leaves yellowing around the edges on the clones. I'm assuming it's nutrient burn. My PPM has been ranging up to 750 or so. I have well water. Not sure if it could also be a cal/mag deficiency.

Thanks!

 

[freezeland2]

Are you planning to defoliate before you start flowering? If so, I would defoliate now so you can let them recover from the stress of that. Then flip em to 12/12.

 

[Panhead59]

Are you planning to defoliate before you start flowering? If so, I would defoliate now so you can let them recover from the stress of that. Then flip em to 12/12.

New grower here but I've read they double in size during flower stage. They are getting big. Looks great !!

 

[growsince79]

How big is the tent and why are they bunched together?

 

[Steveystrappa]

You should probably flip them like now lol things are gonna get out of hand real quick.

 

[Ponky]

For a tent They should have been flipped already. Defoliate. Top. Train. Wait 4 days after that. Flip. They're gunna be tall.

 

[OGHomefry]

Alright thanks everyone. I’m gonna defoliate tonight and flip them over ASAP.