rootbound doesn't make your plant look like that. you can grow in most any sized container and do well. all that is affected is the size of the plant and yield. if all nutritional needs are met, then you're good. a good meter for checking ppm is a good idea but not absolutely necessary. you could probably benefit from one, until you get more familiar with your nutes anyway. you can't really go by what's on the bottle. companies make money by selling you their products. i.e. the quicker you use what you have and buy more, the better! a ph meter of some kind is key. a good stand alone fert. is the way to go for beginners. pure blend is a very good all around fert. i think the pro version is for hydro. i use it early on in veg. and i grow in coco. if you're gonna use tap water, let it sit for 24 hours first, to let the chlorine dissipate. earth juice is pretty acidic so i'd let that sit for a good day too to reduce acidity. in soil, feed once a week. in between plain ph'd water. 6.5 ph, is a good place to be.