...a little more info would be good, such as the current pot size, and what you're thinking of moving it up to, would be good.

Also, how old is the plant? I assume that it is not a youngling, seedling, or clonelet... and are you going to go thru a 'short' grow cycle, or the whole year?

If your plant is showing yellowing leaves that you can't explain ennehoo else, and/or watering it seems to just 'run through', then yes, your plant is prolly rootbound, and it needs to have a bit more room to grow in.

Your lovely lil' darlin would benefit from a pot two to three times larger, but no more. If you still have time in your 'grow schedule', you should think about repotting more often rather than less. You want your plants to grow nice, dense rootballs.

I just repotted a plant of mine that is in its fifth week of flowering, from a 1ga passive hydro pot (peat/perlite medium), to a 3ga passive hydro pot with a 1ga res (sitting in a 4ga pot!), same medium, and you wouldn't believe how much of the 1ga pot the roots took up...

I took a little bit of time to gently break up the root ball a bit, at least at the edges, and just tamped the soil down gently. I am now getting water ready for a full-soak watering that the darlin could more than use...

Mmmm... nice new repotted Numba6.