Over the summer it was the heat. The temperatures in the tent reached upwards of 90 degrees F, and we had to pull the HSP and bring in the Pro-Grow 180 LED grow light.
This morning the 600 watt digital ballast that powered our High Pressure Sodium lamp in the Bloom-Room just upped and died. So I ended up pulling the Pro-Grow 260 from the auto-flower/veg-box, replacing it with a butt-load of CFLs and hanging the 260 in the Bloom-Room, from the light mover.
I set up the Pro-Grow 260 on the light mover, holding very close to the tops of the plants (about 8-10 inches). If it were not on the light mover, I would hold up position about 14-18 inches off the tops.
I hope the replacement ballast gets here soon! CFL’s work fine in a pinch, but the seedlings & autoflowers miss the PAR of the Pro-Grow LED.