well i have run 30x 3L before under a 400, then downsized it by 10 took the 10 smallest and put em outdoors. but i found i like running less, bigger plants, hempys can range from 2L to 5gallon or more, and how large of a garden are we talking?
i like to do Coco now, and have only used a 400w hps but i hear of people doing bigger setups . the guy there was doing perpetual 2L and getting 1/4 oz per 2l, and i think it was 10-20 every 2 weeks under a 600 or something... (the information is there somewhere 3 sets of 10-20 so 30-60 total and each had their own runoff tray. they were cloned and put straight to flower so the mother chamber was huge and he was gettin pretty good at it and then he got bopped, pulled down his images but there are others who do the same type of setup.
you could modify it to drip but that kind of takes the simplicity out of it
i could re -use my coco but i put it in a compost pile then buy more. Each year i use the compost/coco mix for an outdoor grow
i guess for an industrial type grow you could do bigger hempys, but i get that it's going to be a lot easier to do a flood setup; each setup has it's own obstacle i guess
just wanted to hopefully turn you onto the hempy idea, maybe you could try one and see how it does compared to the others in a side by side; just sayin it doesn't need pumps and can drink whatever you're giving the others; just know if using coco it demands a little extra treatment
