MH and HPS lighting basics to know! And how much it could cost to opperate.

[NVancouver]

High Intensity Discharge Lamps (HID's)

High intensity discharge lamps are easier to use, and more efficient. Low wattage HIDs are sometimes sold for household outdoor use. Large Wattage lamps are used for lighting streets, parking lots, stadiums and other large areas. They come in two basic flavors:


METAL HALIDES
or MH lamps emit a white light that looks slightly bluish. They are used to light stadiums, convention centers, gymnasiums, and other large areas where a natural looking light is desired. Good for vegetative growth and sometimes used to flower. I have used a combination of MH and HPS for a mixed spectrum in the past and found it works quite well.

HIGH PRESSURE SODIUM
or HPS lamps emit a orange or amber light. They are used for lighting parking lots and other areas where the color of the light is not important. HPS units are much more efficient than MH ones, producing more light and less heat per watt of energy consumed. They are often used alone with no detrimental effect on the plants, and will promote faster plant growth than MH lamps during flowering, and even veg...but I find it tends to make them strech more.
Combinations of bulbs are NOT always required, as the HPS lamp does produce all of the light spectrums necessary for healthy growth.
There is a relatively now type of HPS lamp that has become available. It is called the San Agro lamp. Basicly the designers of this lamp took a 400w HPS lamp, and added another 30W element to it, However, this new element puts out blue light, to help fill in the parts of the spectrum that a standard HPS is missing. I currently use one of these bulbs, so I can't tell you about how efficient they are.

MH lamps are available in 175,200, 400 and 1000 watt sizes. HPS lamps come in 50, 75, 150, 400, 600, and 1000 watt sizes. San Agro comes in 430w only, but it works with a 400w HPS ballast. Each lamp requires its own ballast, which comes with the fixtures that are designed to use these lamps, and are also available separately. The smaller wattage ones can be found at hardware stores such as Home Depot and larger (400, 430, 600 and 1000 watt) at local grow stores.


The following chart shows how much light each lamp emits, and the area that it covers adequately:

Lamp # of Lumens
4'FL (CoolWhite-40W) 2,960
8'FL (CoolWhite-75W) 5,800
MH 175W 14,000
MH 400W 40,000
HPS 70W 7,600
HPS 150W 16,000
HPS 400W 50,000
HPS 430W 53,000

I currently use a 430W HPS in a 2'x4' area, which is 8 square feet.

Gardens should receive 1000-3000 lumens per square foot at a minimum to flower. Successful gardens usually are lit at around 2,000 lumens per square foot. During the vegetative stage, plants stretch out when they receive low levels of light. During flowering, the flowers are looser and sparse.

So what is the best lamp for growing? It depends on your budget. HPS lamps to me are by far the best overall, but they are also the most costly to purchase and setup and are not the cheapest to operate.

**To calculate your hydro used, use this simple equasion:

Divide the number of watts used into a kilowatt (I use a 430W)
430/1000=0.430 (# of kilowatts used per hour )

Multiply the outcome by your hydro providers rate for hydro consuption, usually can be found as a cost per kilowatt hour used.
Where I am it is 6.95 cents/ kilowatt hour, I would just round it up to 7...

0.430 X 0.07= 0.03 (Cost per hour of operation)

Than how many hours is it used? Currently I am flowering under this 430W HPS so I would use it for 12 of every 24 hours.
Take the outcome for the cost per hour and multiply it by 12 hours.

0.03 X 12 (Hours) = 0.36 (Cost per day)

Than how many days are in a month...average is 30.
0.36 X 30= 10.8 (Cost per month)

That is well in my budget here, $10.80 a month but everywhere differs in the rate that is charged for hydro consuption.


I wish you a healthy and happy crop!

[FreakNature]

Good info.

[NVancouver]

Thanks!
Besides these there are so many other options!

There is a world of CFL's and other various flourescent lights that are becoming much more efficient than the HID's mentioned above.

I will see what I can find...

For vegging I have used flourescents a majority of the time because of the low heat to ventilate out and big savings on the electrical bill.

We should start a new thread for the effiency of CFL's as I have seen some good gardens with only them!
Cheers

[Smokin Moose]

Great post!

[NVancouver]

FLUORESCENT LIGHTING:

Your options for fluorescent grow lights were limited for many years. The standard 2 bulb, 4 feet long fluorescent shop light was just about your only choice. Because of the affordability of the fixtures and the huge improvements in the bulbs themselves, standard fluorescent lights are still an excellent choice.



Choosing the right bulbs is very important to your success. For seedlings, clones, and vegetative growth, you want lots of blue light in the spectrum. Pick bulbs that say "cool" or "cool white". They usually posess a colour temperature that appears as slightly blue, measured on the colour spectrum as the term "kelvin". The K of a veg light is usually 5000 or higher, I have used CFL's up to 6500K. I am not sure of the K of a MH at the moment but I would geuss it could be up to 5000K.



With the right bulbs in place, your fluorescent fixture will provide enough light for plants up to 10 or 12 inches. A single fixture like this is perfect for seedlings and clones.



By using 2 or 3 fixtures above your plants, you can increase the effective light zone to around 24 inches of good light. This is what you need to do if you are growing plants vegetatively to 18 or 24 inches.



Since fluorescent grow lights put out little heat, you can keep the tops of the plants 1 to 4 inches from the bulbs at all times. Even if they touch the bulbs there will be little damage. Mainly it will just be blocking the light.





T5 Fluorescent Grow Lights


This is one of the newer systems. The T5 system uses improved high output bulbs, like the ones I suggest using in the section above. They use several bulbs side by side, and there is an arched reflector behind each bulb.


These lights are designed to support bigger growth. Their best use is for growing strong, healthy plants in the vegetative stage up to 24 inches tall.



These lights are quite expensive, so I would stick to a standard fluorescent light for your seedlings and clones. The benefit to them is the high light output and more light if you would like to flower with flourescents.



One friend, who has been using ONLY fluorescent grow lights, has told me these lights will support flowering. He also told me the yield is about half what you would expect from the same size garden grown under high pressure sodium light but I have seen many gardens that would proove him wrong!



After gardening under fluorescent grow lights for a year to save money, my friend is now getting a high pressure sodium light.





Compact Fluorescent Grow Lights


This is the latest development in fluorescent grow lights. Every inch of bulb surface is a source of extra light, and these bulbs are designed to have a maximum bulb surface in a tiny space.


The designers combined this with the best high-efficientcy horizontal light reflector technology to make the most of every bit of light.



I have been told the performance and function is very similar to the T5 fluorescent grow lights. The price of these two systems is also about the same.





To Put Things into Perspective


I believe the T5 lights and compact fluorescent lights cost around $150-$300 dollars. I have seen standard shop light fixtures at Sprawl-Mart for $7.95. High output bulbs are about the same if not a little more.
I bought a few 42Watt Phillips daylight bulbs here in Canada that were 6500K on the colour spectrum, but they cost me $15 each.


I have been convinced for a long time that you can duplicate the performance of T5 lights and compacts much less expensively. Even if it took you 5 fixtures and 5 packs of high output bulbs and you put together a 10 bulb setup, you still would have only spent about 80 dollars.

There are just so many on the market these days I suggest do your homework. There are bulbs that give the essicnial red spectrum needed for flowering, usually measured about 2200-3000K for the same price, refeered to as "warm white" or "soft white".
Some provide more lumens than others so be sure you get the right bulb for its need.

Good luck!

[adamcat]

exelent read +reps for the info very easy to understand