EelGrowsanswered grow question 5 years ago Hey man. First of all good luck on your first grow from here on out! Second turn on the light full power from day 1! both spectrums are useful! How many plants do you plan to grow under the light? I would move it further away than 20cm for now, since you don't know how powerful it is(and if you decide to turn on both switches). Did it come with a manual with hanging heighs? Once the seedlings pop through the soil, you can judge if you're hanging it too high or low by how much they stretch. If you notice stetching(let's say 5cm) before the develop their first real node(not the cotyledons), then lower the light. Good luck!