White Widow flowering questions (pic)

Plants: 5 WW clones @ week 5 of veg
Equipment: 2gal BB system, 600w HPS (the MH broke...)
Nutes: Distilled water and floragro + epson salt.
Conditions: 80 degrees and 55% humidity.
Cycle: Was on 24 hours cycle, but the room was getting too hot so I switched it to a 20/4 cycle

Question: Ok so I've been vegging for about a month now. The plants are growing at all different heights and I'm not sure when to flower. I've read that WW can reach maturity after 12", but I'm not sure what a good height to flower is. Complicating that is the fact that one of the plants is 5" taller than the others. I thought the others would eventually catch up, but I was wrong, this plant is like Hulk. Should I top it? Or is topping right before flowering bad?

I guess what I'm really wondering is what a good gameplan for flowering is considering the size of the plants.

Any feedback would be awesome. This is my first time growing hydro.

soon as you get pre flowers they are ready. Though i always veg a extra month an supercrop for a bigger yield.

so you think top the big one and keep vegging for a few weeks to maximize yeild?

Nowhere near ready to flower yet unless you have a small room with height restrictions.