High Hein my lights about 30-45cm away, not ideal, but... my grow area is 1.25x1.25 so I need the coverage as well.. plan to add another 250W for my next mega grow, but that's sadly only gonna be in about 3 months time, by then I would have dismantled this setup. What's the size of your grow area? 20cm seems optimum, if you've got your temps within range and uniform light coverage. dont think Ill reach my goal date of harvest 1st week December, will harvest around Xmas, by then i guess Shadow's AKs will be lekker ripe and schweet... thanks for stopping by