Want to transfer plants from smaller pots to bigger

Hi guys

I have three og kush plants that I grew from seeds on May 29. I want to transfer them to fibric pots to grow bigger. What size should I get 20 g 30 g or 65 Gallon.i have attached a picture of the pots they are currently in. Thanks

Whatever you have room for. The bigger the better. I've gotten over a pound per plant outdoors in 15 gallon fabric pots. You should try to transplant soon before they flower.