you really should transplant atleast once or twice roots will stretch to the bottem no matter how big the pot is you should check out airpots if you don't wanna have to replant i use em in combination with coco i see almost identical growth rate as hydro, i transplant into the gal airpots right after solo cups and they stay there the pots are designed to "air prune" the rootsoh and those peat moss plug things are3 awesome, Ill send you some. it keeps the seedling confined like a solo cup or beer can would. but it grows out of the cube into the 3gal pot so it never has to be transplanted.
you really should transplant atleast once or twice roots will stretch to the bottem no matter how big the pot is you should check out airpots if you don't wanna have to replant i use em in combination with coco i see almost identical growth rate as hydro, i transplant into the gal airpots right after solo cups and they stay there the pots are designed to "air prune" the roots