Light change during veg

(copypasta from another post in the newbie thread)

I have a question regarding light changes during veg... I started an indoor grow, 400w HPS / top-drip hydro system using hydroton / GHE 3-part nutes, etc. and I have about 2 weeks of veg left. I started vegging under HPS because that's all I had at the time, though I just got a couple of 400w MH bulbs. My question is - can I switch bulbs (and color spectrum) now, with 2 weeks of veg left, or should I stick to HPS till harvest ? My girls had some heat stress in the beginning, and though I sorted the problem out I don't want to stress them out more with a light change in case they hermie.

Would they handle the stress if any?
Would they benefit from just 2 / 3 weeks under MH before going back to HPS?

Thanks in advance for your infos.

Peace,

you could also keep the mh on throughout stretch to shorten internode length. My opinion is, leave it with the hps ( it is mixed spectrum?) Too often we faff, its better to set it.... Then let her do her thing.

switching bulbs, there's a spectral transitions. Slowing growth for a week while the plant adapts. Imo its best to be using the same light in veg and flower. If changing lighting. Change the bulb or light when there's 2 weeks left of veg. So there's no spectral transition when flipping to 12/12.

if your HPS is not Dual spectrum , i would suggest you switch it to MH for a better Vegging and get a dual Specturm for flowering , your plants will thank you cause they can benefit from the blue specturm during flowering it is proven that it increases THC production due to more UVB output , if your hps is dual spectrum , just leave it , next grow start with the MH from the beggining.

Thanks for your replies, so I think that as long as there is growth I won't fiddle. By dual spectrum I take it you mean a HPS that puts out at around 4000k ? My HPS is 2100k and my new MH is 6400k.