I wouldn't worry too much about being rootbound that late. You figure you only have four weeks to six weeks left and they plant shouldn't be growing alot more roots , you want it to be consetrateing on buds , not roots. if you go with a bigger container tyhen your plants are going to finish and there will still be unused soil. Why waste the soil. If you have a easy source of soil and a stealthy way to get it in and out then it's kind of ok. I personally wouldn't waste the soil. You want to use just enough soil to get the yeild that you wantthen don't waste te otyher soil. Use just enough to get what you want from the plant, Ie, if you want them to be mothers then use at least five gallon to ten gallon hieght permitting. We use five's for mothers and three gallons for clones as we are not asking for alot of hieght from are clones we can easilly do them in three gallon containers.
Are you going to be going with a mon plant set-up? If so you are going to need to get another 400 for your vegging. If you have ten clones every two weeks thats going to be thrity under floes and almost fourty under vegging. As well as fourty in flowering. You can see wheer you get into some big numbers really quick. You can harvest ten plants every two weeks though. You can go with just two moms that way you will only have four plants every two weeks. This would be alot more reasonable numbers. You would have 12 in floes and 16 in vegging. as wellas 16 in flowering. Anyway good luck with your progect.
