Coming from hydro is it normally acceptable to up pot during flowering? What are the signs? yellowing lower fans?
Best
LT
Yes. (For indoor grows) people do limitate root by using small container until stretch is done and flowering occuring strongly, they do so both to manage the plant size and for easiness of plant care during the last part of blooming (lets say for like 8 to 16 weeks as stretch is generally no longer than the first eight weeks of flowering). If not, tropical/equatorial plants tend to stretch to the moon and grow forever / outgrow the area.
For timing it's just like repuk said:
the moment you see your girl green fading and concentrated on hair throwing, means she's ready for up-potting.
But keep in mind if done too early it may extend your flowering time.
Now if you got a greenthumb, you could also keep them in small pots all along. All you have to do is to find the right feeding routine, kinda just like hydro. That way you could grow much more plants and eventually find a keeper more easily.
All this is not specifically about zamaldelica but growing tropical/equatorial sativa's indoor in soil. Or such kind of plants profile. It won't work with anything too much indica tainted as it will kill the yeild.