nicksol, im going to offer constructive criticism. 1000w for a 5x5 tent is a wee bit overkill for various reasons, and I will start with this....there can be such thing as too much light, unless I missed it you didnt mention anything about CO2 dosing, and in that space with that light is a must do
second, 600 watts are actually best efficency with best watts per lumen, so if you have done the research you said you have done then you would have seen this on many forums, many youtube videos, and even in the cannabis bible.
Scrogging a single plant in DWC is your best chance of getting your dream first yield, but this takes lots and lots of training (fimming, topping, lst, and supercropping), it also means you have to have your eye glued to any deficiencies, overdoses, bugs, molds and fungus and react quick to fix them.
Another variable in yield is strain dependent, what you see someone getting a 1.5 pound out of 1 strain doesn't mean they will get it out of the next strain they grow
So take your time, keep the plant alive and learn your danger signs in the leafs, steams and the environment around the plant