if youre growing in dirt, dont worry about ph testing. If u notice problems flush the dirt completely with water and rewater with reg strength nutes. if u follow the directions on the fertilizer youll be fine tho.
if u must grow in such a short space then sure, line u up some clones and let them root good. then when they get about a ft high, bend the top of the plant and fasten it to the container with a breadtie or something use ur head. then flower and get some weed