When do I flower small plants?

I'm growing some reggie seeds in a hydroponic setup, and so far they're about 4 or 5 inches. The problem I have is is that the light is attached to the hydroponic setup and only goes up to maybe 2, 2 1/2 feet. If I flower them when they're at about 12-18 inches would the bud be done flowering by 2 2 1/2 feet?

i know with kush if you flower when its about 6 or 7 inches it wont get much over two feet but idk about reggie. give it a try and see what happens. it should work. if it gets too tall just lst it

You could air top them and be safe most of the way. This would help reduce the overall height. But, you could flower them now no problem. )

sweet. Gonna start a grow journal then