I was under the impression you can easily veg under a HPS light. The plants would simply grow shorter and more bush-like then under a MH. Now I've got one bloke who says that HPS should never be used in veg, and that it's the reason I'm having such colossal problems with soil.
...it's the other way around man, the HPS delivers more red light which promotes stretchier plants while the MH delivers more blue light which promotes shorter, bushier growth.
...and you can absolutely veg under HPS and you'll get lots of growth, but the downside is you'll get taller, stretchy plants with lots of distance between the nodes so you end up with lots of smaller buds spread over a lankier plant rather than fewer, larger buds because, being shorter and bushier, the buds grow together more on a plant that was vegged under MH.
...you can also flower under MH quite successfully so don't take as carved in stone anything someone tells you can't be done until you try it and prove to yourself it can't be done, ...often you'll find that it can, in fact, be done.
peace, bozo
Will post how it goes.
