I was hoping to find someone that has run say a 600hps and a 1000hps in the same space with the same strain, etc. that had seen it with their own direct experiences
I used to run 600W HPS X4 flip flop. Even in a basement, the heat was out of control unless I cranked the AC in the summer or shut down some of the lights during the hottest parts of the day. The yield and quality was adequate but sucked compared to DIY LED, summer or winter. Same cutting same nutes etc.
Some good friends have gardens with daisy chained 1000W Hortilux HPS w cooled hoods and some use 600W Hortilux HPS w cooled hoods. Using the same cuttings, soil grown with liquid nutes, their yields were only slightly better than mine. I have seen them get as high as .9 gpw with high yielders (ISS) but it took 10+ weeks to finish (sloppily) and the quality was not even remotely close to the dank cuttings grown under LED.
Granted the 1000W DE should be an improvement over my generic 600s. Can't say that I have tried that yet but I doubt I would be willing to sacrifice the space or take on all that heat to test it.
Next question would be, if the photosynthesis is sufficient to grow huge plants at lower wattage pre-flower - what is it about the higher power that directly influences flower size and weight?
They say big roots = big fruits. So if you veg sufficiently in a large enough container, don't under fertilize and dont over fertilize, flower with 750-1000 PPFD average, sufficient airflow without letting CO2 levels droop too much, you should be able to accurately explore the genetic potential of most varieties. If you allow the canopy temps to rise to 86F in the first 5-6 weeks of flowering and run a large yielding variety, you should be able to grow some monster sized buds. May be able to push them even further with skilled force feeding via hydroponics but that is beyond my experience.
I would add that
bigger is not always better. Large buds tend to shade their own insides and are more susceptible to white mold deep inside the buds. It also seems that the larger yeilders can be susceptible to dreading/taking forever to finish, which can lead to a mixture of over mature, mature and immature trichomes . That is what I am referring to as a sloppy finish and I suspect interferes with potency.
What I am really chasing is maximizing yield while maintaining top quality