so you are saying that if you put one of these MH conversion bulbs in a standard HPS ballast (not digital), it will work?
Yes, as long as the wattage of the bulb and the ballast match. The "conversion" part specifically refers to the bulb being outfitted to run in a HPS ballast. A MH ballast and HPS ballast are the same except that HPS requires an igniter, a separate element that sends a huge surge of electricity to the bulb at start-up. HPS is designed to work that way, MH will explode. A conversion MH has something in it that absorbs that initial surge and allows the MH bulb to work off that ballast.
To the original question: For what it's worth I and a lot of folk have found that High Pressure Sodium lights work perfectly for the entire cycle. The only thing I found was that some of the plants, not clones, seemed to be less green and more yellow. Probably that's to be expected. It can tend to put one off the HPS solution, but in the long run the yield and potency is still there. Using MH,s seems to increase the leaf yield during the flowering stage at the expense of buds, altough it does depend on the strain of seed or parent of cuttiings. But I'd use HPS throughout the process, no trouble at all. Good luck with your project, stuckinschool
If 100w. of anything adds to your elect. bill which makes you think its "HUGE",YOU SHOULD NOT BE GROWING!!!
this is my understanding on the subject HPS light is slightly more intense and will grow plants in veg a little quicker but it will cause the plants to stretch more. the MH light will grow them a little slower but the nodes will be tighter. Also the leaves might be greener when you grow under MH. For flowering, its HPS all the way due to color spectrum. If u have money for, or access to, only one or the other I would go with HPS Thats my 2 cents. GL
If you're set on a 100W HPS lamp, I'd suggest a security light from a home improvement store. While you're there, pick up a few light fixtures and mini-spiral CFL bulbs (Daylight). That will provide both ends of the spectrum used for photosynthesis. Either mount everything in your closet or build a light hood out of a storage tote.
yea i def think the hps is the best choice and if u have the budget go ahead and buy the conversion bulb there is this good web site that have light ballasts and everything setup so all u have to do is plug it in ... here it is htg supply http://www.htgsupply.com/growlightsubcategories.asp?categoryID=1 i think every1 will agree that they are good to buy from hell they even give u a lighter with the balla
I had originally thought that UV would be a benefit to an indoor grow but didn't have any evidence to support that. I had read a report (can't find it again right now) where there wasn't any significant increase in yield or potency when using UV A-B so I didn't pursue that. Do you know of any additional studies on the effect of UV light on plant growth?