Grow light to plant distance

Hi buddy I go about every 100 watts at 10 cm distance :-)

During flower not vegging. for vegging try around 750 or so.. They like all the extra light but you don't wanna be hurting the foliage just yet so don't risk the 1000 zone until stretching stops and flowering really starts this is also when it is most important.

I've gotten 10 inches close to similar panels with no harm to the plant. But I'd say 12 inches tops for comfort.

If you don't have CO2, it's a waste to get closer than 24" the middle will be a hotspot for sure at 18". I think 24" gives best footprint for a 4x4, anyway. still will be hot i middle... not just heat, but photons. the light won't be wasted... if you have a light meter, evena cheap one.. if you ever rotated it a bit will takeing measurements, you'll noticed with this light at 24" it likely will have excellen side-lighting. as you rotate, it'll maintain a slightly diminished measurement as when straight up at light. So, it's not lost. Makes sure you stay below threshold that require CO2, or if oyu have CO2, ~1500 is ceiling, if i recall? FYI thats for bloom... in vege and expanded hours, you likely could burn your plants or cause them to wilt at that height and in middle. 700 (same value they use in their chart) is about as high as you'll want it over ~18 hours. Again, can go higher with CO2, but consider you have 50% more hours too. 65 is a generally considered max DLI. (see a DLI chart in my week 4 or 3 or either diary)

Personally I'd say 12 inches as long as its spread is large enough to light ur entire canopy area at that height.

Pretty much follow their green blue and red numbers as Seeding green, veg blue, and flower red. You use it as a guideline and slowly adjust your lights till you see your girls praying in the morning! Cheers and happy growing!