I assume that it is your first time with these strains, so you don't know from experience how long you want to take them. What did the packages say for flower time? I am growing some that say 65 days, but I am going to be more like 75 when I cut em. I flush for the last 2 weeks. First week RO water with molasses added. Second week just RO water. If one strain is more done, you can always start flushing them independently. That's what I'm doing right now. I got a Super Skunk that is an early girl and she is ready to go. I just have another week of flush then she's all mine!
-TF