I have this light someone gave to me and i cant find anywhere on it to tell if it's a high power sodium of if it is a metal halide. I kinda think its a metal halide by the color of the light but idk to much about these bulbs. I'm hoping it's a HPS because my plants are in flowering stage. I'll put some pics up and you guys tell me what you think. If this is a metal halide would it work for flowering? I know HPS are best for flowering but i cant afford that right now.
Hps is usally a straight tube. MH is straight then gets big in the middle, then straight again. MH kinds looks like an onion. mH^ ^HPS
A lot of folks use mh for vegetative only and then some use them for the last few days/weeks of flowering as they claim it helps with trichrome development. I'm not entirely sure if this is true or not, plus, could never justify the price of a mh for vegetative only. I usually stick to cfls for vegging and hps for flower. If you do hps the whole grow, youll have stretched internodes, whereas cfls/mh lights cause the nodes to be much closer resulting in buds that are thick and close together compared to spread out.
i think i read MV used to be used to power old street lights. not very efficient and very hot with a poor spectrum....CFL would be better
Could it have something to do with the color of the light? A blade of mine had a 250w HPS accompanied by a 400w UV light for the later half of flowering. He told me the UV would increase trichome growth but do nothing for the bud size itself. Now that I look at my 250w MH, it's almost the same color as the UV. Am I onto something or just rambling? EDIT: It does definitely have a connection with color. "3. High Intensity Discharge (HID) lamps - These include metal halide (MH) and high pressure sodium (HPS). These lights are traditionally used for lighting large areas such as gymnasiums, warehouses and parking lots. Today, they are the primary choice for indoor plant growth. HID lamps are 4-8 times more efficient than incandescent lamps. These lamps have a high light output, (and produce a lot of heat) so they should be placed about two feet or more above the top of the plants. Metal halide lights have a wider range of wavelengths so they are a good all purpose light able to be used in all stages of plant growth, seedling, vegetative and flowering. I use high pressure sodium which have a higher intensity of light per watt compared to MH, but they also emit more red and yellow light. This is great for promoting flowering and fruit. In spite of this, they are not the best light source for seedlings. A MH conversion bulb is a good option for vegetative growing plants, but it may be more economical if you have the room to have one area with fluorescent lights for seedlings, and young plants, and when the plants get bigger put them in another area where you promote flowering." Source: http://forum.grasscity.com/lighting/263178-all-about-lighting.html