Omega black 720 led…. Iv never used led before I...

Hello buddy i have a very similar light it uses a hps ballast to power the leds mine is also 720 watts the distance should be between 30-50cm though it should be in the instructions that came with your light as most of them are different but usually within 30-50cm the intensity wont matter much until later on I usually keep my seedlings on 240 whatts which seems to be fine for me and then when in veg I just turn it all the way up :)