Mango kush and white widow not x

First time grower using a 1000w mh and 5gal rounds. Now the mango and ww have been veg for 5 wks Mango looks awesome. Bout 9" another 7" all 3 widows about 4-5". Is 4-5" good after 2nd day in beginning of 5th week. I want to start flowering now so that the mango doesnt get to tall but I don't want the ww to lose because of not waiting for it to reach 12-16" before flowering. Think I'd still get a good yield

any pix? you could take the ww out of the room and give it some light in another room to keep it in veg longer.