IM no expert that's why i don't feel ashamed telling this, i transplanted mine when it was that size into a pot that size. It is growing awesome buds and very tall but it is not big enough. When i stick my finger down into the soil to check for dryness i can feel roots which tells me I've either underwatered or i needed a bigger pot. I've read you should have 8 inches of soil per foot upward. Like a said not an expert just tried.to read up as much as i could on everything. Good luck