When should I transplant it again ? info on this is all over the map..10 inches up to 2 ft they say ???
It really depends on a lot. What size pot is it in now, how much harvest are you aiming for, what light (spectrum, wattage, type of bulb) do you plan on flowering in, what medium are you using, are the roots properly rootbound or are they a rootball, what strain, is it auto or photosensitive?
First, Transplanting is an eh thing to be doing to the plant. Just like most plants that produce an abundance of flowers, weed hates when you start messing with her roots. Transplanting seedlings/clones regularly is not too bad a thing to do, as sizing up pots,
THEORETICALLY helps increase the root system at an even rate meaning the whole pot is guaranteed rootbound in its final container. But stressing the roots can lead to hermies. Most people will tell you to start in the final pot and be patient.
The root systems tends to imitate their canopy structure and vise versa so a wider than deep pot is recommended. A 1.5 oz plant 3 ft tall at the top at harvest would likely be found in about 3-5 cubic feet of soil.
So anyways if you have the say 4 40w cfl then a good pot size would be 1.5-2.5 gallon (probably a 16" pot). If your roots have reached the bottom of your pot, and circled around a bit, its best to get into the final pot as soon as possible.