Ah, the Mars Hydro lights, I currently run 2x Mars Hydro 150w TS1000s, so pretty close to what you are doing. I keep em high and let the plants grow up into them.
Seedling/Sapling 100% power - 60 inches, this'll put you around 9000lux, 70umol.
Veg 100% power - 36 inches - gives you 20-50k lux and 150ish-400ish umol
Flower 100% power- 18-24 inches give you 50k-70k and 400-700ish umol.
Hope this helps.