I use 5 gallon. I just finished emptying the Maui from its cloth pot and the roots completely filled the pot. I started out using 3 gallon cloth pots and I would get issues that I guessed came from probably experiencing the early stages of being root bound. I am going to add a Moroccan belita to my next grow and use a 3 gallon because I am only going to veg it for maybe 3 weeks just to give it a try.