Specific Answers, Please

A customer has a question and I hope we can get some opinions on it, thanks.

“I live in Georgia and would like to grow some plants inside but have never been able to get a VERY SPECIFIC ANSWER as to what lightbulbs (model, etc) and where to purchase them, and how to hook them up. Cost and operating costs are issues but would like to produce a pound in ten weeks”

Specific answer go to Amazon search for 1000w grow light you should be presented with lots of options cheapest being MH/HPS combo’s they come with ballast cord bulbs and shade hang the shade and plug in cords which only plug in 1 way done you have your light


The cheapest route to start with would be Compact Fluorescent Lights (CFL).
Fixture: Big Box stores will have something called a work light or brooders light. They are about 10" in diameter. I got a lamp extension and three "Y"s. Put the lamp extension in the center socket and then one of the "Y"s, then put the other two Ys into the first one where you will have provisions for four CFL lamps.
The lamps needed are 150w equivalent which use around 40 actual watts. For VEG use the daylight color range which is somewhere close to 6500 Kelvin spectrum (close to blue).The ones Lowes Home Depot are EcoBulb Daylight. Part Number of light is ESL40TN/D For flower use a soft white, lower color spectrum (closer to red) which is 2700 K. Part number ESL40T/ECO.
This set up is fairly inexpensive to start with and doesn’t get too hot so you can place them pretty close to your plant(s). Down side is they are not dimmable.
Philips make CFLs that are 100w equivalent which doesn’t emit as many lumens. They pull around 23w actual.
For LED lights we’ll have to bring in some of the forum experts.
I hope this is SPECIFIC enough for you.


I see journals all day with budget 600 watt mh/hps yields over a pound. Same with homemade 400 watt led builds. I don’t know how many of them do it in 10 weeks though. Even with 7-8 week flower times you’re looking at probably 4 weeks veg time to develop the required branching. Autos would be an option, but would require more floor space.

How big of a grow area are we working with?


Well first let me welcome you to ILGM AND " WE ARE VERY SPECIFIC " with our answers
here at ILGM.

I can be very specific and for starter’s check this out my friend

This is very large hope it’s not to much but you did say be specific

Marijuana Lights or grow lights enable the grower to extend their growing season to the whole year. Marijuana lighting also give growers a large amount of flexibility in the growing process. Because the marijuana grow cycle is dependant on the hours of light the plants receive, artificial lights enable the indoor grower to begin the flowering process whenever they want. There are naturally disadvantages to using grow lights to grow marijuana. They often cost quite a bit especially the good ones. Also there is the cost of the electricity. Growers usually use either MH (Metal Halides), HPS (high pressure sodium lamps) and Fluoros. As a rule of thumb, MH work best in the vegetative period and HPS work better in the flowering phase. A combination is often used. Fluoros do work, however they are usually in commercial marijuana lighting.

Read below for a more detailed knowledge or check out a complete guide to weed lights at Grow-Marijuana.com.

The amount of light that marijuana receives determines the quantity and quality of the plant and buds. The photo period is the number of light hours verses dark hours in 1 day.Marijuana usually needs 12 hours of dark each day to begin flowering.

Under continuous light Marijuana will grow but will not flower and produce buds. Darkness makes the plants produce flowering hormones and regular undisturbed darkness will make them stop growing and start flowering.

Outdoors the seasons control the photoperiod. As the summer comes to an end and the nights become longer cannabis flowers ready to produce seed. Indoors you control the photoperiod so you can start flowering whenever you wish.

Sunshine is more intense than any artificial light and is free. However some places on earth just don’t get enough. Greenhouse growers can supplement sunshine on dull days with electric lights hung in the greenhouse.

The most efficient types of marijuana lighting are sodium or metal halide high intensity discharge (HID) lamps. Metal halides are strong in the blue spectrum of light and are good for growth. Sodium lights are strong in the red spectrum of light and are good for flowering.

High intensity lights also come with different shades. All combinations work OK but its best to use sodium bulbs in horizontal shades for flowering. Plan on giving 30 to 60 watts of light for each square foot of growing space.

Lights get hot and can burn plants that get too near. However the closer the light to the plants the more intense light they receive. In general keep 400 w lights 30 to 45 cm above plants and 1000 w lights 45 to 75 cm above plants.

Fluorescent light is fine for the growing stage but flowering plants really need more intense HID light. If fluorescents are your only choice choose alternate rows of “Cool White” and “Warm White” bulbs and place them only a few cm’s away from your plants.

Marijuana grow lights

The purpose of this FAQ is to help limit the spread of misinformation regarding effective artificial lighting systems, and help those who choose to grow marijuana plants under artificial lighting make an informed decision before buying a grow lamp.

Most of the information comes from printed sources, and some from electronically distributed files. Though information also comes from a network of experienced growers who have tried various types of marijuana lighting.

This FAQ is not going to tell you how to use your lamp, that information can be found in most grower’s guides.


There are three major types of lighting systems available right now for growing marijuana:incandescent, fluorescent, and high intensity discharge. Incandescent lights are horribly inefficient (especially the screw-in “grow bulb” type) and really not an acceptable option for marijuana plant growth. Although they are inexpensive to purchase, their cost of operation makes them the costliest source of light. Therefore avoid at all costs.


Until the early 1980’s most indoor marijuana growers used fluorescent lights to illuminate their garden. These tubes have tremendous advantages over incandescents. They emit about 3 times as much light as an incandescent (given the same wattage), and the light spectrum is one that plants con use more effectively.

However, they do certainly have their limitations. Light is emitted over a large area, so it is not concentrated. Because of this, the lights have to be hung very close to the plants, and constantly moved to accommodate plant growth. This makes garden maintenance rather difficult. Marijuana plants can often grow very quickly increasing the times the lamps need raising. To add to this, in the flowering period, fluorescsent lights are not effective making them a poor choice for lighting marijuana plants.

Fluorescents are, however, very useful in cloning, and starting seedlings. Because in these stages, a plant is not growing vertically very quickly, the disadvantages of moving the lights are reduced. They also put out a more gentle light than the HID lamps, and release less heat.

If you choose to use fluorescents, it is best to purchase the ‘cool white’ variety or a mix. The ones that are sold as grow lamps (including grow-lux, vitalite, etc.) are much less efficient than a standard fluorescent, and just do not put out enough light to be useful. The slightly different spectrum produced by these lamps does nothing for most plants.

High Intensity Discharge Lamps (HID’s)

You will find pictures of marijuana lights here.

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.

High Pressure Sodium or HPS lamps emit a pink 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 both vegetative growth and flowering. Combinations of
bulbs are NOT required, as the HPS lamp does produce all of the light spectrums necessary for healthy growth.

MH lamps are available in 175,200, 400 and 1000 watt sizes. HPS lamps come in 50, 75, 150, 400 and 1000 watt sizes. Each lamp requires its own ballast, which comes with the fixtures that are designed to use these lamps, and are also available separately.

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

Timers for the garden

The lighting system needs to be switched on and off automatically so the marijuana plants receive 18 hours of light per day during vegetative growth and 12 hours per day when flowering. most hard ware stores and other electronic shops sell timers. they are usually very cheap . It may be advisable however to purchase a more robust timer if your serious like a pool timer.

Lamp # of Lumens Sq. Ft

4’FL (CoolWhite-40W) 2,960 1-2
8’FL (CoolWhite-75W) 5,800 2-4
MH 175W 14,000 5-10
MH 400W 40,000 12-20
HPS 70W 7,600 3-6
HPS 150W 16,000 6-11
HPS 400W 50,000 15-30

Marijuana grow rooms should receive 1000-3000 lumens per square foot. 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.

When choosing which marijuana lights to use in your garden, we suggest a combination of MH and HPS with flouros used in cloning and early seedlings. It is also important to chose the right shade. Some will reflect light much better than others. Any good supplier should be able to recommend the best for your requirements.

Now how’s that for Specific and i have even more



@garrigan62 there’s a ton of great information there! But I’m wondering why you didn’t mention led lightning? Furthermore, when you say hid are the most efficient, in which way do you mean? I believe in this field efficiency is best measured in grams per watt. Last I knew the modern led lights were easily over 1 g/w in the hands of a reasonable grower. But the hid guys are still boasting about how getting there is some sort of a milestone. Am I uninformed, or is this information slightly dated?

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@garrigan62 I love you brother that is how it is done lol nice work Will your little piggy to the west lol :pig:

The light spectrum for growing is far better than L E D in other words better yield my friend

For the many growers who are unable to cultivate cannabis outside in the free abundant sunshine, grow lights are necessary to successfully grow cannabis indoors. Grow lights take the place of the sun, and power the growth of your plants and their buds. Light is like “food” for your plants, so without a lot of bright light, even a healthy cannabis plant won’t produce much bud at all.

More Light = Bigger Yields!
(up to a point, it is possible to give your plant too much light!)

There are lots of options for grow lights that work well for growing cannabis indoors but in the end they boil down to 3 major types:

1.) Fluorescent Grow Lights

Compact Fluorescent Lights (CFLs)T5 grow lights (and other fluorescent tubes)

2.) High Intensity Discharge (HID) Grow Lights

Metal Halide (MH)High Pressure Sodium (HPS)Ceramic Metal Halide (CMH, LEC, Light Emitting Ceramic)

3.) LED Grow Lights

(LEDs come in a huge variety of sizes and form factors. There aren’t really any “standard” types yet, though some lamps get better results than others.)

Note: Some growers may have heard of “Induction” grow lights, which are pretty rare these days but still pop up from time to time. There are two types: “Magnetic Induction” grow lights do okay for growing cannabis but they’re pretty much glorified fluorescent lights. “Plasma Induction” grow lights actually perform pretty poorly at growing cannabis.

Some types of induction lights are well suited to stadium lighting but honestly they just aren’t that great for growing cannabis and they come with huge price tags. Even a lot of LEDs are cheaper and you’ll get better results with them. You can learn more about induction grow lights here.

Note 2: Incandescent light bulbs (old fashioned light bulbs) are NOT suitable for growing marijuana!

Compare the Pros and Cons of Each Grow Light

1.) Fluorescent Grow Lights

Fluorescent grow lights come in many different shapes and sizes, from twisty bulbs to long tubes. Fluorescents are popular because they make efficient and pleasant lighting for humans, and also work great for herb gardens and other types of low-key indoor gardening without using a lot of electricity.

Read full tutorial on CFL grow lights

Read full tutorial on T5 grow lights

CFL Grow Lights

CFL grow lights are the twisty-looking bulbs you can find anywhere you normally buy light bulbs. They produce a great spectrum for growing cannabis and can be used in tiny spaces where no other grow light would fit such as the inside of a cabinet.

Keeping CFLs close results in the best yields and growth

Learn more about CFLs

T5 Grow Lights

T5 grow lights are one of the most easily available types of grow lights and are used to grow many different types of plants. As a result, they’re available in many garden and home improvement stores.

T5s are much bigger/wider than CFLs and usually come as part of a panel, but they can still be kept mere inches away from your plants without worrying about burning them.

These cannabis plants are thriving under T5 grow lights

Learn more about T5 grow lights

Pros of Fluorescents

Cheap to buyThey don’t use a lot of electricity or make a lot of heat unless you have a lot of them packed together in a small spaceGreat light spectrum for growing cannabisSince lights can safely be kept just a few inches away from plants, they’re a good choice for short spacesOne of the best lights for clones, seedlings and young plants. Big lights must be kept far away from young plants to avoid burning them, which ends up wasting a lot of light and energy. By using smaller lights like fluorescents while plants are still short, you can save quite a bit of money on electricity during those first few weeks compared to using a high-powered grow light.

Cannabis plants under a T5 grow light - when plants are trained (like these ones in a Scrog setup) you can get pretty decent yields from fluorescents.

Read more about CFLs vs T5s

Cons of Fluorescents

Fluorescent grow lights get smaller yields per watt than the other types of grow lights if you use them in the flowering stage while buds are forming. With fluorescents you can expect about 0.25 grams of buds for every watt of electricity (using the true watts out the wall, not any type of “equivalent” watts), while LEDs and HPS get 2-4 times as much yield per watt of electricity.The light from a fluorescent lamp doesn’t penetrate far down into the plant so they are best suited to plants that have been trained to grow short and flat; they aren’t powerful enough to support tall plants in the flowering stage.

Example of CFL grow setup which yields up to half ounce per month

Fluorescents are a great choice for clones, young plants, supplemental lighting and can save you money on electricity in the vegetative stage compared to using high power lights when plants are too young to use it all anyway. They can also be used to flower plants in spaces that are shorter than what’s possible with other grow lights (aka ‘stealth growing’).

That being said, when it comes to the flowering/budding stage, if you can fit a bigger light you will get significantly better yields/watt by using an HID or LED grow light!

Learn more about T5 grow lights

Learn more about CFLs

You might be interested… More on CFLs vs T5s

2.) High Intensity Discharge (HID) Grow Lights

HID grow lights are much more efficient than fluorescent lights and are powered by large, oddly-shaped bulbs. They are usually screwed into a reflector or hood to reflect more light down onto the plants. HIDs are great at growing cannabis, but they also get very hot and are usually hooked up to an exhaust to help vent out heat.


Full tutorial on MH & HPS grow lights
(most common grow light combination for cannabis)

Full tutorial on CMH / LEC grow lights
(LEC stands for “Light Emitting Ceramic” and is a type of Metal Halide bulb that is built with ceramic like an HPS - basically it’s sort of like a blend between MH and HPS bulbs)

Metal Halide (MH) Grow Lights

Metal Halide grow lights are generally used for the vegetative stage because they produce a bluish light that vegetative plants love, though this type of light can also be used all the way to harvest.

The light from a Metal Halide appears a little bluish, and is well suited to growing cannabis plants in the vegetative stage

Learn more about MH grow lights

High Pressure Sodium (HPS) Grow Lights

High Pressure Sodium grow lights are often used during the flowering stage because they are very efficient and their yellow light stimulates bud production. HPS grow lights in the flowering stage get better yields per watt of electricity than any other type of grow light available today, which is a big part of why they are so popular.

The light from an HPS appears yellow, and is great for flowering plants because the light spectrum stimulates bud production

Learn more about HPS Grow Lights

Ceramic Metal Halide (CMH) & Light Emitting Ceramic (LEC) Grow Lights

These are actually just two names for the same thing. This type of metal halide bulb uses ceramic as part of the lamp just like an HPS. As a result, CMH bulbs are more efficient than regular MH lights (though still not as efficient as HPS bulbs).

Lately I’ve been seeing CMH grow lights these labeled as “LEC” lights, which stands for “Light Emitting Ceramics.” Since LECs are the same thing as CMH lights, personally I think the term “LEC” is used to make this seem like some new type of light, and in order to ride on the popularity of LEDs…

“LEC” and “CMH” both refer to Ceramic Metal Halide grow lights, which is a type of HID light that is a bit more efficient than a regular Metal Halide light

Learn more about CMH / LEC grow lights

Pros and Cons of HID Grow Lights


HIDs are the most efficient type of grow light (gets the highest yields/watt).Of all the HIDs, HPS grow lights are the most efficient and the best for the flowering stage. When using HPS grow lights in the flowering stage, you can expect about 0.5-1 gram/watt if all goes well.HID lights are simple to use because they can be hung the right distance from the plants with no guesswork on your part (unlike LEDs), and no need to adjust the lights all the time (like¿ fluorescents).

HID bulbs get really hot and generate a lot of heat. Because of the concentrated heat production, you will almost always want to put the bulb in a hood and also provide some sort of cooling to prevent heat from beaming down onto your plants and driving up the ambient temperature of your tent/grow room. This is especially important for the bigger lights with power above 250W.Additional setup - As a result of the heat mentioned above, most growers use an exhaust fan with ducting to vent out heat. Unfortunately, the prospect of having to deal with the fan and ducting scares off many growers from HID lighting.More parts - HID lighting means a few more parts than other types of lighting. Fluorescents are just the bulb and a fixture and most LEDs are just the light itself. But most HID setups have at least a bulb, fixture, an external ballast and an extra cable if you don’t count the exhaust systems parts, too.

Example of MH/HPS Setups That Yield 1-5 Ounces/Month

250W HID

1-2 oz per monthElectricity: $69/month (including electricity for fans)Initial Setup Cost: $605.00

400W HID

1.5 - 3.5 oz per monthElectricity: $96/month (including electricity for fans)Initial Setup Cost: $744.00

600W HID

2.5 - 5 oz per monthElectricity: $128/month (including electricity for fans)Initial Setup Cost: $780.00

There is a larger size MH/HPS grow light available (1000W), but at that size it starts going outside the scope of a “hobbyist” grower as far as ease and yields. In addition to needing a lot of extra cooling which costs electricity, a 1000W HPS grow light is less efficient compared to a 600W grow light (as far as how much light is put out for electricity used). I think most hobbyist growers would be happier with a 600W, or even two 600W lights, over a 1000W :slight_smile:

HIDs are very well suited to growing cannabis and very easy to use once they’re set up. If your main goal is to get the highest yields possible, then HIDs are the way to go! However, they do require extra setup compared to the other grow lights because chances are you will need a fan to vent out heat from your grow space.

Learn more about MH / HPS grow lights

Learn more about CMH / LEC grow lights

3.) LED Grow Lights

LED grow lights are very popular among cannabis growers as an alternative to HPS grow lights. They tend to run cooler and also usually come with built-in cooling. They can often be plugged into a wall and simply hung over plants which is definitely easier than setting up an HID grow light. LEDs also have great penetration so they don’t need to be moved frequently like fluorescents.

Simply hang an LED light over your plants and start growing!

Learn more about growing cannabis with LED grow lights

You might be interested: 5 Barriers to Total LED Grow Light Domination!


LEDs almost always have built-in cooling that pushes heat up and away from the plants (unlike HID bulbs which beam heat down on your plants and need to be cooled separately). As a result LEDs run very cool and many growers are able to get away without venting heat at all. The smaller size LEDs can be plugged directly into the wall and hung up over your plant, without needing to do anything else. You can just plug them in and start growing!Some growers believe LEDs produce more resinous bud. Combining LEDs with HPS grow lights seems to be getting some growers really great results, though more testing is needed.


Although the LED lamp itself usually does run a lot cooler than a similar wattage HPS bulb, they still produce heat and the bigger sizes like 300W+ may need to be vented with an exhaust fan to prevent the grow space from getting too warm.Despite what some sellers may tell you, LEDs get slightly smaller yields per watt than HPS grow lights on average (LEDs commonly yield about 0.5g/watt, though some growers and lamps get better results than others!). There is a learning curve when it comes to getting the best yields from your LEDs, partly because each lamp is different and there are no “standards” to go by yet. A little experience with a specific lamp can improve your yields by a lot!LED grow lights tend to need a lot of space between the lamp and your plants, which means you need a tall grow space to get the best results. This is actually the main thing holding me back from trying LEDs more. Smaller LED panels should be kept 18" or more away during the second half of the flowering stage to avoid light burning your buds (buds can be burned from too much light even if the temperature is cool), and some of the bigger models need to be kept 30" or more away from the buds. When in doubt, contact the manufacturer!

If you get very high-wattage LEDs, you may need to vent out heat to keep the grow space cool

For growers who are looking to harvest 1/2 to 1 ounce of cannabis a month, LEDs may be your best choice. At this size, they are super low on electricity, run cool and need almost no setup! They get better yields than fluorescents but don’t run as hot as an HPS of similar wattage.

Here’s an example of an LED setup that yields up to 1 ounce/month

Note: When shopping for LEDs, make sure they contain some amount of green orwhite (full spectrum) light. If you see an LED lamp that only has diodes for red and blue light (which was very common in older models), don’t get it! Plants grown without at least a tiny amount of green or white light are very prone to nutrient deficiencies and simply don’t grow as well. Learn more about how light spectrums affect cannabis growth!

Learn more about growing cannabis with LED grow lights

You might be interested: 5 Barriers to Total LED Grow Light Domination!

Now that you are familiar with all the most common cannabis grow lights I hope your choice is a little easier. I wish I’d had this information when I first started growing indoors :slight_smile: Happy growing!!!

Wrote by
~Nebula Haze
posted by


Yes, it is true, as for the starting cost, and on average, HID lights are about the best thing around for growing.

However you are not wrong in the knowledge that some LED lights can indeed get you 2 to 3 grams, or even more per watt used by the light.

And many LED lights that are for sale just don’t fit the bill.

To learn more about the types of LEDs that can give you these results without having to buy the most expensive main name brand LEDs you will want to check out “Grow Mouse” on youtube, spelled growmau5. And in fact, if you want to know about some of the best, and unfortunately very expensive, LEDs systems out there, he has some awesome info on those as well.

Happy growing,



Very nice @MacGyverStoner. I always get the feeling that there are still so many people comparing blurple leds to hid lighting. That’s so 15 years ago. I do agree that that $300 will go much further for initial investment with hid. However, modern diode offerings from cree, bridgelux, Samsung, and luxeon are plenty capable of providing the same if not better spectrum than hps. All that heat left from hid lighting is wasted energy. I wouldn’t go as far to say led is the end all be all. Hid still has its place due to cheap start up costs. But we’re seeing 5-10% efficiency boosts just about every year from the major led players. So the $2-3/watt good led lights cost is dropping regularly.

In my opinion, led technology surpassed hid 3 years ago, and is still getting better. Average growers are already matching hid yields using 30-50% of the electrical energy. And they are getting more affordable as time goes on.

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I’ve built a system with seven pairs of 23 watt cfls arranged as six pairs arranged as a hyexagon around the central pair. Think of six equilateral triangles radiating around a central point. The sides of each triangle is very close to 8". Makes for some difficulty screwing bulbs into the “Ys”.

14 bulbs at 1600 lumens = 22,400 lumens.

I’m growing one plant in a box that’s slightly less than 2x3 ft. 《6 ft2). 22,400/6 = 3,733 lumens/ft^2.
At 8" below each triangle is a point ( apex of a tetrahedron) where the plant gets light equally from 3 pairs of bulbs.

I am definitely keeping the tops closers than 8". Boy do they grow nicely.

I can bring in the sidewalls with temporary walls to cut some wasted space and up the lumens/ft^2. I might just build a hexagonal box to make more efficient use of space.

Pipe dreams include a computer controlled stepper motor to rotate the plant to equalize the exposure to light. Due to the shape factor, anything more than 60° /18 Hours would be excessive in vegetative phase.

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Uh, maybe we should ask some specific questions. How big is the Grow room?

What’s the lighting budget?

With a 600w hid system I got for $150 I can Grow about 12 - 16 oz in approx 120 days, starting from seed in a 4’x4’ area. It takes more veg time to get up to 16.


@pH_6.0 you have any pictures of your setup?

Do you veg for 6-8 weeks to get that yield??

I have been vegging between 60 to 90 days depending on how they are doing. I want to have my full Scrog one layer deep from edge to edge and three nodes up on the branch growth before flipping. It gets massive but it’s fun.

I watch the branch thickness too. I want them to thicken up before flipping then they will get even fatter during flowering and will handle the weight I get from them.

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You can contact with Mars Hydro for help. They can recommend suitable light to your customer and they also have repair center and warehouse in your country

I have a question first timer 2x2 tent and growing autoflowers would a hlg 100v2 3000k light be good for 3 plants or a viper spectra 600 w 12 band led