Hey!
Clones and seedlings: 2,000–4,000 lux
Vegetative growth: 15,000–30,000 lux
Flowering: 45,000–110,000 lux
There a lot of people who say
there’s a maximum amount of light 75,000 lux and that above that can cause bleaching on the leaves etc...
I personally have recorded more than 100k in my tent and have had not problems with light stress. But you have to pay attention and move your lights up whenever it’s needed.
Also.. don’t try to just go for the minimum, it’s best to go for a bit more and get a good crop going.
My advice is follow your light’s manufacture’s guide on the light distance in stages that way you have a general guideline to follow and can go adjusting from there as you examine your plants growth.
Hope this helped.
Good luck and happy Growing!