No Problem growmie, as ive already grown with the SF-1000
You start with adistannce of at least 70 cm with seedlings, and just let them grow towards the light
if you see your plants yellowing, dwarfing... rise the liight
if i have new lights i always start slow, and each strain is alittle ddifferent but the 70 cm has shown as "sweet spot"...
but pls check it back by yourself......
it is better to start with low light, than nuking them.
I never used the dimmer knob on the sf1000.....
i started on 100cm... and found the area around 70 cm was the right one......