Space for plants and lights needed

running co2 or not? The easiest way is to break down what you need per sq ft (or m^2, etc) then you can scale that up and know your requirements for any size area. Watts are not what you want to use, because efficacy of each light you can buy will be different, so you'll need varying levels of watts. With such a large operation efficacy (umol/J) becomes more important. Spend more on the lights now to save a lot more money each month in electricity and increase longevity of lights by comparison too. win-win. Assume without co2 and you can do the same math for any context.. Over 12 hours, you want about 650 PPFD to reach ~38 DLI give or take -- these numbers aren't exact because hanging distance and reflective walls will impact the decision too. This is probably erring slightly on high side, too. 650 / 10.76391 = 60.38698. 60.38698 * 1000 sq ft = 60386.98. So you want well distributed lights that amount of 60,400 umol/s of light production. Again, the watts required to produce this much light will vary, so umol/s is a better way to figure this out by far and twice on sunday. A high efficacy light will be 2.8umol/J or better (this is specifically for the diodes, driver efficacy draws this down a bit as well as light that simply misses the plants). 60,400 / 2.8 = 21,571 watts for high efficacy options... more for the cheaper options with lower efficacy. So, ~22 lights if they are 1000w and well distributed to spread the light out properly and fit with the other lights to cover your area... common sense on that stuff, if you can use a ruler and do basic multiplication and division. co2? target of 55DLI? 55/38 = multiply the above umol/s target by 147%, maybe a bit more depending on how much DLI you want to give with the supplemented CO2. LOL, gonna need some industrial strength dehumidifiers. Fun exercise even if bullshit. Break it down into a common increment and scale to target size.. easy-peasy. Math don't lie. how many plants is about how long you intend to vege them - a choice and not random. if your target plant size is 1-1.5sq ft in a sea of green, simply do the math.

The fact your asking means you probably shouldn't attempt such a large grow

I agree with Scrubbyjimbob.

I would suggest if you're unsure of the answers to this question then you probably really have no business trying to set up a grow of this scale. Layout is important here. Is this 1000 sq ft area the size of the room or actual canopy space...you're also gonna need space to access the plants so if that is your room dimensions your canopy size will probably be closer to 800 square ft. Is this like a 10×100 space? 20×50? With the indoor rooms where I work we work with about 1500sq ft of canopy(double stack racks), we run about 90 lights for about 1400 plants per room. This is a pretty crowded, SOG style grow though. You could easily fill such a space with half the plants with a little more veg time and proper plant training.

Prob need about 40 1000w led fixtures. At max you cld cram 1000 plants. Cld grow about 250 plants large