autoflower light cycles

Hello I have a friend growing an autoflower pink diesel x amnesia and its beginning to flower. He was wondering if he should put it under a 1000 watt hps at 12/12 or keep it under his 400 watt metal halide at 18/6 any help would be great thank you :thanks:

I have been seriously been considering a crop of autoflower. I have been doing some research on them and keep hearing reviews, of which vary, across the board. I guess I just have a few more questions that may seal the deal for me... so it would be great if anyone could shoot me some advice/...