I think a FAIR notice should be mentioned in the information FAQ

[md.apothecary]

Just a little VENTING (pun intended)

I read through a lot of old posts and of course the new posts with everyone asking questions about lighting.

Hardly ever did I see someone mention one flaw with lighting when giving opinions and advice to those looking for lighting.

Do NOT automatically assume 400w of light is the best for your grow.
Do NOT automatically assume more INTENSE light is better for your grow.

You MUST take into consideration cost of lighting, type of lighting, required lighting, and HEAT issues.

Sure, 400w is the "standard" people think of when they think of HPS and MH light sources. People spit 400w recommendations out all the time, even for a micro grow unit! Unfortunately, for me personally, I found this was not the way to go.

HEAT issues for getting too large of a grow light will COST you more in the long run than being cautious and smart about your initial choices on your lighting. I think people need to realize that more intense light is not necessarily the way to go. Each setup will be unique to your own needs, and while I am not discouraging your posts on what lights to get, make sure you fully understand that you're going to have to cover all your bases. You will need more than just a light, so don't go strictly by what someone tells you.

:ignore:

 

[dnlfacundo]

so if you wanted to do a 4 or 6 meduim sized place and wanted to get a qp you whould use cfls.

 

[akirahz]

so if you wanted to do a 4 or 6 meduim sized place and wanted to get a qp you would use cfls or hps.

Uh yeah.. are -- are you feeling alright??

 

[md.apothecary]

You can't necessarily go by saying you want a QP by saying you are going to have so many plants. Your strain will dictate this, NOT necessarily the lighting. Some plants put off 500g per plant in optimal conditions. That there is over a LB right there. If you had 4 plants that putt off over a lb a piece that's a lot of stuff!

HPS is optimal for flowering, however, you may not NEED a large HPS to make your quota. You might just need a 250 and some white paint.

 

[Hick]

..I believe that hps are "more efficient" than cfl's. More PAR lumens per watt spent. And.. if I'm not mistaken, 10,000 lumens of cfls produce the same amount of heat as 10,000 of hid.

http://www.ahlgrows.com/lighting.html

Types of Grow Lights

Incandescent Grow Lights like those sold in nurseries or hardware stores are not powerful enough to grow most plants. Incandescent bulbs also have short life spans and are not energy efficient.

Fluorescent Grow Lights are good for starting seeds or cuttings, but typical fluorescents are not powerful enough to light an area more than 8-10" below the bulb. Fluorescent bulbs are more efficient than incandescents, but much less efficient than HID light systems. However, there have been some exciting recent developments in fluorescent technology that deliver much more light than regular fluorescent bulbs. Hydrofarm's Compact Fluorescent Light System, and Sunlight Supply's New Wave and Tek-Light T-5 products, are so powerful that they can take plants through at least part of their vegetative growth. The advantage of these fluorescents is that they produce so much less heat than metal halide or high pressure sodium lights. With heat eliminated or greatly reduced, lights can be placed much closer to plants for maximum efficiency.

HID (High Intensity Discharge) light systems have revolutionized indoor gardening in the last 20 years. They are the most energy efficient grow lights available, so they produce much more light for the amount of power consumed. The two most common HID lights for plant growth and maintenance are Metal Halide (MH) and High Pressure Sodium (HPS). Metal Halide bulbs emit a balanced light spectrum which appears blue-white to the human eye, and High Pressure Sodium bulbs emit a spectrum which is more concentrated in red/orange light.

Most gardeners use at least 25 watts per square foot of garden space. You may need less than this if your light is used to supplement natural sunlight, or if you are growing a plant that does not require as much light (such as lettuce). On the other hand, many gardeners prefer to double or even triple the recommended wattage to achieve faster growth rates. These gardeners also must pay close attention to the garden environment due to the intense heat produced by HID lights. There is really no such thing as too much light, but using a big light in a small space will sometimes result in high temperatures that are difficult or impossible to control.

 

[md.apothecary]

According to that post, it says that CFL produce far less heat than MH and HPS. Which is the advantage to using CFL's. Again, it's a balance of your personal needs. I need less heat for my location and growing styles, and from my trial and error 400w of HID lighting was simply too much for my closet, switched to CFLs, dialed in my proper lumens (400w was WAY over what I needed in Lumens) and the heat was reduced dramatically! No fan needed to cool a closed closet, it's simply for air circulation now.

LEDs are virtually no heat, good VEG but very minimal flower production, hope one day there will be new LED technology that produces better results in flowering.

 

[Mutt]

I spit out the 50W of HID/sq.ft. rule. If you don't have the room then 400W is not the answer a 100W or even a 70W in some one plant grow conditions.
IME 120W worth of HPS (70 and a 50) with the ballast remote produced less heat than the (3) 55W CFL's producing less lumens....its all in appying the right amount of HID...just becuase the 400W is too much doens't mean you can't step down the HID wattage...HID is the way to go in flowering hands down...just use less wattage IMO.

 

[guatemalacoolestdude]

nice debates but all with knowledgeable resources. thanks team MP.

 

[octobong007]

now your lumens is still 3,000 minimum and 5,000 equals perfect, per square foot? and should you go by full space or plant space?

 

[md.apothecary]

Would be really no need to fill unused space, BUT if your light filled unused space... USE IT

However, it's about what we call in MY industry "blocking". You'll use your space requirements for the amount of plants you intend to grow and block around them to create a reflection so that space utilizes more light that would naturally fade into unused space.

The ONLY issue I have with HID light is that approx. 80% of it's visible light source is in the form of heat. I have 315w of CFLs (3 x 105w) and it's never hotter than 85 degrees flux, with a 400w HID in same space it was well over 100 degrees constant!


However, when I obtain some more money, I will be attempting to reduce the HID light wattage and going for a 250w, but that won't be for some time.