purpleman
Here is my thoughts on pot size
You are running a 450 W purple light which has an actual power draw of 200 watt and it isn't reasonable to expect 6 Plus ounces per plant, the people that tell you that grow under 1000 watt HID lights in big rooms, so Make your environment the best for what you have work with and dont buy into delusions of grandeur.
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A 3 gallon smart pot with coco perlite mix and a good nutrient line will allow quick root development to fill a pot which will cut down on your veg time to get you to flower faster. I think that a small pot is a better choice under a lower watt light then us big light guys use, Coco and smart pots will also be better than your hardware store brand soil and five gallon buckets, it is reasonable to say you can pull 4oz up underneath that light with two plant and on a good day you could see more.
If you are going to want/need to produce more I would think about looking at another light, hlg has some great lights for the money, COB light are picking up and the ture work horse for cannabis mh/HPS.
I am not going to argue over genetics and will let you make that decision for yourself the fact is you're the one growing it so you'll know best and In my opinion no matter who you get seeds from there is always a Chace for a unstable/lame genetic or phenotype. If your environment isnt dailed in there is no way to have a control or comparison for what good, bad, or great is, so I would start their.
what nutrient line are you going to run with that coco?