Flowering question

When do you know when to start flowering. Do you go by hieght age or what?
Probably a dumb question.
Thanks
S

it depends. how much room you have, the style of growing your doing,and your own personal tastes all matter.

Which bulb is better for flowering MH or HPS. Keeping in mind quality is the most important thing for me.
Thanks
S

a high pressure sodium with added blue spectrum or a ceramic metal halide are best. they have both spectrums plants need. if i had to pick one of those 2 i'd go with the hps w/added blue spectrum, if i had 2 hid lights to pick i'd do one of each.

Definitely HPS for flowering (most new balasts are switchable and can run a MH for veg and then flip to a HPS for flowering) and when you put them into flowering is up to you. I personally think they do best with a 2 months+ veg period so they fully develop before kicking them into flowering. Some people flower them after just 3 weeks of veg. I'd say as long as they have at least 3-4 nodes go for it. One thing you might consider though is that they will double or even triple in size during flowering so maybe just go by how big you ultimately want them to get. Peace. =)

as long as you dont have an electronic ballast the ceramic metal halide is made for hps ballasts as well.(dont try w/a electronic ballasts unless you like wasting money and buying new equipment. lol). I A hps ballast will run mh, hps, or cmh just fine. It's safe to do so, but i must warn you it can slightly shorten the life span of mh bulbs to run them in a hps ballast. Not enough that it actually matters imo, but the ceramic metal halide does not posses that flaw and has the extra red/violet spectrum added as well.

They are about 18 inches or so one is an autoflower I think it's starting to flower so I wanna get the others going too. You said they can triple in size when flowering that would be rad