When to change pot size?

Hi all,

I'm growing 6 seeds currently from my previous indoor grow. I have them in small pots, probably 0.5lt. Now because the seeds are from my previous grow I dont know which will be male or female until further down the line.

I want to put the females in to the biggest pots I can, but at the same time I dont want to transplant all 6 to big pots as half could be male and it will cost a lot in wasted soil.

I'm aware ill have to change the pot size once from these little ones to 11lt I'm thinking, but my question is, once I've identified the females, can I then transplant them again in to big pots 25-50lt for the stretch and rest of growth? Or will this be too late?

Thanks

wait till you need to start watering nearly every day. They can prolly get to about 18" in those 2 gallon pots. use good soil when transplating put in 5 gallon then a 20-50 gallon