Got two GG#4 under 1000 watt HID. Wondering if during stretch it would be better to keep MH instead of switching immediately to HPS. Does anyone have and input on this. Any help from the experts would be appreciated.
I run HIDs both in 1000w.
With my seedlings, I run my 1000w MH with the ballast dialed down 50%. Keeping the light over 3’ above the plants. After a couple weeks, and once they gain some size, I dial up the ballast to 100% for the remainder of veg.
At the first sign of pistils and flower, I switch out the bulb and place a 1000w HPS @ 100% for the balance of flower.
Good luck.