Stop what your doing and read this and remember. I messed around trying to get more production out of my 1000s. After reading some threads saying their 1000s were at 10 inches and 18 inches I lowered mine. Also pumped up nutes to 1400ppm from 1200....End result fan leaves burned as fuck!
Did some research...If you have a good reflector you light should never be closer that 3 ft. It is pointless you have all the lumens you plant can take. Raise your hood and get better diffusion from refracted light and a larger footprint. 1000s are rated for 6x6 area. I use 4x4 tubs and the plants end up at 5x5. I use PL lights that have incredible coverage and light distribution. under the center of the light reads the same foot candle readings as the corner of the grow area.
If you feel like burning your plants lower your lights.

Disclaimer..you could run more airflow & keep the room cooler & keep nutes lower than normal & shut off Co2....etc but why? Your plants want uniform lighting and that is achieved through distance and refraction. That is an argument for running "less effecient" 1000s instead of 600s.

Drawback...height restrictions...

Good luck friends.. -J