Switched hps to 600w. Hortilux.
Turned off hps this time for photos. Co2 now at 1000. Vent fans need to run more often now with hotter bulb so less spray time.
Flushed media with FloraKleen to break up salts.
@criticalkushweed, It seems to like it! I pushed my last strain to 1800 ppm as measured with my Bluelab meter without any burn. I'm going to try pushing this crop a little harder when stretch is done. I'll switch the 400 HPS to a 600 and return the co2 to 1200 in about 2 weeks.