hps are unmatched in flowering capabilities and mh are unmatched in their vegging power as their respective light spectrum is optimal for that stage of growth. so here's what i'd do if you can afford it, get a conversion bulb(a bulb that emits mh spectrum on a hps system) and use that for veg than switch bulbs as you move into flower. if this isn't possible then yes the hps will be fine all the way through
This is some Good Advice, Also, here are some RIU Faqs
Metal Halide - MH
Metal halide bulbs produce an abundance of light in the blue spectrum. This color of light promotes plant growth and is excellent for green leafy growth and keeping plants compact. It is the best type of light to be used as a primary light source (if no or little natural sunlight is available). The average lifespan is about 10,000 cumulative hours. The bulb will light up beyond this time but due to the gradual decline of light, it is not worth your while to wait for the bulb to finally burn out. If you compare their lumen (brightness) per unit of energy consumed, metal halides produce up to 125 lumens per watt compared to 39 lumens per watt with fluorescent lights and 18 lumens per watt for standard incandescent bulbs.
High Pressure Sodium - HPS
High pressure sodium bulbs emit an orange-red glow. This band of light triggers hormones in plants to increase flowering/budding in plants. They are the best lights available for secondary or supplemental lighting (used in conjunction with natural sunlight). This is ideal for greenhouse growing applications.
Not only is this a great flowering light, it has two features that make it a more economical choice. Their average lifespan is twice that of metal halides, but after 18,000 hours of use, they will start to draw more electricity than their rated watts while gradually producing less light. HPS bulbs are very efficient. They produce up to 140 lumens per watt. Their disadvantage is they are deficient in the blue spectrum. If a gardener were to start a young plant under a HPS bulb, she/he would see impressive vertical growth. In fact, probably too impressive. Most plants would grow up thin and lanky and in no time you will have to prune your plant back before it grows into the light fixture. The exception to this is using a HPS light in a greenhouse. Sunlight is high in the blue spectrum which would offset any stretching caused by HPS bulbs.
HOW MUCH LIGHT DO I NEED TO VEG CANNABIS PROPERLY?
It all depends on what light you are using, if its HID, standard fluoro or compact fluoro (I assume you're not using halogens!). For HID (HPS or MH) lighting, use roughly 30w per square foot, and for flowering use around 60w per square foot. This is merely a guide, your plant, light height; reflective surfaces etc make a huge difference on these numbers. For a small plant, below 1ft tall, Id say you would need at least 25w of fluorescent light. I find that it isn't at all practical to use tube fluoros for the vegetative stage past 6 inches, as only the top of the plant is receiving enough light to carry out photosynthesis properly.
Using an energy saving compact fluoro will help 'push' the light to the base of the plant, assisting photosynthesis. If the plant indicates it needs more light by growing slowly, and with small leaf petioles, you may need more light. Go with the basic rule of keeping the fluoros very close, and using roughly 20-30w per square foot for strong vegetative growth. If you can afford to over-light your grow room, why not? You wont regret it when your plant is bushy and healthy. If you feel that you need to only purchase a minimum amount of lights, you probably shouldnt be growing.
Growing takes effort and money, and if you can't support a plants needs you might as well just forget growing until you can afford a proper setup. Skimping on lights is the biggest mistake a grower can make, because photosynthesis is so important to for a health plant.
WHY IS A HID "BETTER" THAN A COMPACT FLUORESCENT?
HID lighting is generally accepted as a better light for growing cannabis for a few reasons...
· It has much better light penetration
· It is much more powerful (higher lumen output)
· It is stronger in light spectrums suited for growing plants
What can we do to combat these problems to make the most out of our fluoros?
· Use a good reflector. Desk lamp reflectors are perfect, along with coke cans (cut in half from top to bottom).
· Purchase lights with high energy saving capabilities (e.g. high watt ratings)to increase light penetration
· Purchase lights with suitable spectrum strengths for each phase of growing (eg warm white, cool white etc.)
· Keep the lights close to maximize intensity
NOTES:
· For good results, these lights must be used with a good quality reflector. They give of 360 degrees of light (in a 2D cross-section) but you will only really need 90 degrees of light (maximum). Building a reflector will help concentrate all the light to the area needed, instead of wasting it lighting up the ceiling of your grow room!
· Although you can successfully grow and flower a cannabis plant under a fluorescent, your results will be poor and you will most likely be disappointed. Use these lights only for seedlings and clones, and perhaps the vegetative stage of the cycle. A HID light is recommended for flowering.
Yeah, those Sunpulse Bulbs, sounds like some hectic Shit, but presumably 1 probably will have better results, but probably not that significant when using the same wattage in relative comparison to having to keep up with changing Bulbs, I bet they are on the Expensive side as Well, Have to check'em OUt and see...
