Beginners Guide to Selecting an Indoor Light Set-up

in Beginners Starting out Fri Nov 22, 2013 5:20 pm
by ozzydiodude • The Weird One | 2.474 Posts | 11542 Points

Beginners Guide to Selecting an Indoor Light Set-up

Posted by SmallPotatoes at BB

One of the things I enjoy most about these forums is talking with folks who are brand new to growing or who have dabbled a little bit and are ready to take the next step. When it comes to indoor growing, people get really excited and want to take bigger bites than they can swallow, and I ought to know as I am the worlds worst. One of my biggest problems is that I daydream a lot about “the ultimate grow room.” I think about multiple lighting set ups, big light movers, mother rooms, clone rooms, hydroponics, carbon dioxide, ozone generators, fans, plumbing, electrical wiring, etc. By the time I am done, I have about 100 times more growing space and stuff than I actually need.

I find with most things I try to accomplish in this life that it is very important to set some sort of goal. Cannabis cultivation is no different. I think that the most successful growers are successful because they know what their goals are, and, most importantly, they know their limits.

It is important for those who are considering indoor growing to think before they make their first purchases. I have put together some things that I think will be helpful for new growers to consider when deciding to buy indoor growing equipment.

Section 1: The Legal Stuff
Before you do anything, you need to ask yourself if you are ready to commit a felonious act. If you are growing, most cops/district attorneys/judges are going to assume you are selling. For those of us living in the USA, www.norml.org has a wealth of information regarding state laws, penalties, and what to do if you get busted. We live in a world where most people out there think we want to kill them, steal their property, hurt their families, and poison their children. Most of these people have never smoked pot and are simply uninformed. Until we change our society’s view on our favorite hobby, we are screwed and we had better never ever forget that.

Section 2: Define Your Goal
How many people will your grow benefit?

Are you going to just grow for yourself? Are you going to grow enough for you and your wife or husband? Are you going to try to grow enough for your whole family?

My advice to you: Don’t grow to sell and be careful with your generosity. I realize that some of us do profit from our efforts, and I do give weed away on occasion (makes me feel good). But for every person who knows you grow, you dramatically increase your chances of getting caught. Hopefully your wife won’t turn you in, but your alcoholic Uncle Larry who also has a cocaine problem that you didn’t know about might spill his guts to the cops if he thinks it will get him out of trouble. When it comes to selling, you involve people you don’t even know. Enough pressure on the end user will lead to the person who sold it to them.

I don’t recommend selling (there I said it again), but I do give it away sometimes (I said that again, too). You don’t have to tell someone you are growing in order to give them some pot. You can say “Hey, I got you some bud for an early Christmas/your birthday/etc.” They’ll be happy, and will be none the wiser.

Also, if you give someone some weed, and they know you are sitting on a large stash, it might tempt them to rob or hurt you for that stash. Hopefully we don’t have people around us who would do that to us, but a non-destructive amount of paranoia can be a good thing.

Set your goal.

After you have determined how many people, you need to set a realistic goal for how much bud you will need every month or every year. Be realistic, be reasonable.

Section 3: Determine the size of your grow space
Growing marijuana indoors requires space. Depending on your situation, you may have a lot or a little to dedicate to this. Maybe you have an extra bedroom, bathroom, or closet. Maybe you have room in your attic or garage. Maybe you have an outdoor building. Wherever it is you decide to grow, realize that this space is your biggest liability. It must be protected and made secure.

Wherever this space will be, realize that you are trying to create a grow environment where temperature, humidity, air circulation, odor and light are all going to be controlled.

My advice to you: Don’t grow weed if you don’t own where you grow. If you rent and grow weed you are putting yourself into the mercy of your landlord. If they don’t know you grow, you could face instant eviction or arrest if discovered. They do have a key remember, and sometimes (whether right or wrong) they like to take a peek when you aren’t there. Maybe it is a courtesy visit where they are changing the air filter. And on the other hand, lets say your landlord does know and he or she is cool with it. They are still human and are capable of changing their mind. They might even decide to double your rent if they know you are flowering or demand half of your product to keep them quiet. Also, don’t try to conceal a grow if you are living with someone who is putting a roof over your head out of the kindness of their heart. That is bad karma, and it is disrespectful to decide something so serious for someone without his or her input.

Section 4: Start/Stop Grow or Perpetual Grow
Depending on what goal you are trying to reach, the amount of risk you are willing to take, how big is your grow space, and the type of grower you want to be, one of the following grow styles may be a better fit for you than the other.

Start/Stop Grow - This is probably where most of us first started and is by far the simplest way to grow. Here you plant a seed (or two, or three, etc) and grow it out (cutting down the males probably). You harvest your precious females and yield a certain amount of bud. You put your grow equipment up, and don’t pull it out again until you need it.

One advantage to this is that there are times where you are not growing. This limits your “get busted” potential. It might also help when pot-unfriendly people come visiting during certain times of the year (like Christmas).

Two disadvantages. The first disadvantage is that you don’t maintain a mother plant. As you will read below, growing clones from a choice mother plant affords you greater efficiency and the prestige of knowing the quality of your harvested bud before you start your first day of your flowering light cycle. The second, and potentially the biggest, disadvantage is that in order to keep up with the amount of bud you smoke, you will have to grow more plants than you would normally have to if you were growing perpetually. Therefore, if you do get caught during your growing time, you will probably be in more trouble than if you were perpetually growing a fewer number of plants.

Perpetual Grow - Here you are always growing, and there are a lot of different types of this.

Mothers and Cloning
It takes a lot of time and effort to grow a cannabis plant to the point where it reveals its sex. It is kind of like a lottery or gamble as to whether it will be a male or a precious female. Having a mother plant from which you cut clones gives you the certainty of knowing that all of your clones will be girls. Of course some varieties are different, and even a clone can reverse sex or go hermaphrodite if you aren’t careful. Having a mother plant will also guarantee the quality of the bud you are growing. Once you master how a clone performs from rooting to harvest, you will know what you need to do to keep it healthy, and you will know the quality of the finished product based on past experience.

You can choose to keep a mother tucked away and just cut a few clones when you need it, or you can have multiple moms and cut clones frequently to keep the bud supply steady. Either way, you are perpetually growing and you will need to plan your life based on your grow space, however small or large, being perpetually active.

Starting only from seed
You can also perpetually grow without mothers. Here you may have a vegetative light cycle room (24/0 or 18/6) and a flowering light cycle room (12/12). As the plants get big enough, you move them from the veg room into the flower room. You will constantly be looking for males, and you will require a constant supply of seeds.

Another way to perpetually grow without mothers is simply starting seeds again in your grow space as soon as your previous plants are harvested. This keeps your area smaller. Here again you will need a constant supply of seeds.

Let's help each other, by spreading our knowledge of the plants we love
Scroll up


RE: Beginners Guide to Selecting an Indoor Light Set-up

in Beginners Starting out Fri Nov 22, 2013 5:22 pm
by ozzydiodude • The Weird One | 2.474 Posts | 11542 Points

Section 5 – Determining an indoor lighting strategy
So, you know how much weed you need and how often you need it. You have a space where you can grow. Now the big question…..

How much light do I need?

First let me say there is a big difference between the amount of light you need to properly vegetate your plants and how much light you need to flower your plants. I use about one-third the amount of light for my seedlings/clones and about two-thirds the amount of light to vegetate my plants as I do to flower my plants. The flowering stage of the cannabis plant is very light hungry. The estimates I am going to give you relate to how much wattage you need to flower your plants. From there you can say you need about one third the light for seedlings/clones and two thirds as much light to vegetate your plants.

Now, I am going to do my best to give you an idea of what to expect. Your individual results WILL vary, but this will work for you as you are planning your grow space. As you improve your indoor growing skills, you will get better results out of your light. This isn’t exact, just a go by.

Sizing your light is a two step process. Ideally, you want to have plant and bud growth under the entire area covered by your light, and you also want to make sure you are covering as much area as you can with your light. If you are not doing these things then you are wasting light. Obviously if you try to flower a 1 foot by 1 foot area with a 1000 watt HPS, you are going to waste a lot of your lighting coverage. By the same rationale, you shouldn’t expect to efficiently flower a 10 foot by 10 foot area with a 400 watt HPS. There is a lot of information out there regarding the appropriate garden size for varying wattage-sized lights. We have some great info on this in our Grow FAQ’s (hCIp://www.breedbay.co.uk/forums/faq.php). A good rule of thumb is, when it comes to flowering, your light shouldn’t be spread any thinner than 50 watts per square foot. This means a 400 W HPS should cover about a 3 foot by 3 foot area. In the flowering stage, your 2 bulb, 80 watt shop light will be hard pressed to effectively cover an area equal to its own size.

The second step is to determine how much bud you can expect for that light in that space. Some of you may find it easier to do this step first and then do the above step second. Every situation is different, so do whatever works for you. When you are considering how much light you need, you need to look at how much light you are going to use to flower your plants. You also need to consider what type of light this will be.

Fluorescent Light

If you decide to use fluorescent light as your primary flowering light source, you will need at least 6 watts of light for every gram you desire to harvest. If you want to harvest one ounce, you are going to need at least 170 watts of fluorescent light. This is a very loose estimate, and with the advancements in compact fluorescent lighting (CFL) and very high output (VHO) fluorescent lighting, it is quite possible to do better than this in the near future.

ITeachYourKids! is one of the many talented growers on this site who has great results with fluorescent lighting. Here are a couple of links that will show you some fluoro grow examples.

High Intensity Discharge (HID)

HID lighting is probably the most efficient method of primary lighting that indoor growers have at their disposal. Our excellent moderator, Pistils, has a thread here (hCIp://www.breedbay.co.uk/forums/showthread.php?t=252) that explains the different types of HID’s.

I will go against my nature and spare you a lengthy discussion on light spectrums and wavelengths and simply say that typically metal halides are better for vegetative growth and high pressure sodium lights are better for flowering. With this in mind, you will need 2 watts of HID light for every gram you desire to harvest. If you want to harvest one ounce, you will need about 57 watts of HID light.

Sticky Lungs is another of our talented growers who has done well using HID’s in small spaces. Here is a link to one of his cabinet grow threads

Chronical, one of our site moderators has some good HID grow information in the following threads.

Some will tell you that one of these is definitely better than the other. The truth is, you will enjoy or be better at one of these than the other so as far as hydro or soil goes, that is up to you. If you have never done hydro before, I would start with soil and experiment with hydroponics as you get more comfortable with your indoor set up. If you have multiple rooms, this will be easier as you can compare soil and hydro results. Here are some pros and cons for you to consider when deciding between soil and hydroponics.

Pros: Once figured out you should expect bigger yields. You have more control over where your plants are in their stage of life.
Cons: Constant trips to the hydro store or buying online. Depending on your area, this might be risky. Hydro is more expensive to maintain and is a lot more work. You need to have a good grow space that is easy to work in as far as draining reservoirs and mixing nutrients.

Soil Growing:
Pros: Easier to get started and maintain. It is easy to achieve average results with soil. Fantastic results are a little harder. As you get to know your plants you will find ways to improve yields. Subcool only grows in soil as far as I know, and he is a master who is always going to produce fantastic results. It will also be easier to buy components for soil growing more discreetly.
Cons: What are you going to do with all that soil when you are done? If you have a lot of land, this won't be a problem. If you have nosy neighbors, they may wonder what that huge growing dirt mound is in your back yard. There is a lot of heavy lifting associated with soil growing. Those 3-gallon pots get heavy.


Hey, this stuff is great, but I have never used it. I would consider this to be an advanced technique that is beyond the scope of a new grower. There is plenty of info on this (and a lot of people willing to help) on this site. I feel comfortable in saying that if you get this mastered, you could probably double the results of your light power (Section 5) that I estimated for you.

Section 7 - Examples
I thought I would put my method where my mouth is and give you new indoor growers some examples.

Case 1 – I only smoke about ½ ounce per month and I don’t have a lot of room.

This works out to be only 6 ounces per year. I would use the Start/Stop method of growing. If you can dedicate an area of about 4 feet by 4 feet, you could use a 400 W HPS, or you could use a 250 W HPS cabinet grow (about 8 square feet) maybe twice a year to achieve this result.

If you have a closet and are willing to perpetually grow, you could try a 4-foot, 4-bulb, T5 fluorescent fixture, and with good strain selection and experience, you could reach your goal.

Case 2 – My wife and I burn through 4 ounces a month, and we have an extra bedroom.

Holy Big Bud Batman, you need 3 pounds (1.36 Kilos) of bud every year. Let’s say that bedroom was 10 feet by 10 feet (3.05M X 3.05M). Let’s also say that you will be able to perpetually grow.

Step 1: 4 ounces is about 114 grams. Now, with this much bud, fluorescent flowering is out of the question in my opinion. Also, being a perpetual grow, I am going to need a vegetative/mother area in this room. Now, lets begin the light sizing. Looking at the flowering stage, I am going to need:

114 grams X 2watts/gram = 228 watts of HID to generate 4 ounces.

Another thing to consider is that a good fast flowering indica strain will need about 8 weeks of flowering time. If you want a sativa, then you need to plan on a 10 to 12 week minimum flowering time. Lets say we are going with an average of 10 weeks. If it takes us 10 weeks to grow those 4 ounces, then we are missing the mark. So if we say there are about 4 weeks in a month then:

228 watts x (10 weeks for flowering/4 weeks per month) = 570 watts

Step 2: So theoretically if I had 570 watts of HPS, I could generate my 4 ounces per month. Now we need to consider the sizes of lights that are available and the area they would cover. If I were to use a 600 W HPS, I could satisfy my requirement. Remember, I said you don’t want to spread your light thinner than 50 watts per square foot:

600 watt HPS/50 watts per square foot = 12 square feet (About 3.5 feet by 3.5 feet)

You could stage your grow such that you got 4 ounces per month or you could grow it all at once and grow 2.5 months worth at a time.

Experience tells me though that with a room this size, I could maximize this 600 watt light with a light mover. I could cover an area about 3.5 feet by 7 feet and effectively double my area. Now it becomes a lot easier to reach my goal.

So I have sized my flowering light. Now I need to think about my vegetative space. I would personally prefer to have mothers if I am going to perpetually grow, so I am going to need space for mothers and newly cut clones. Using my rule of thumb method for sizing vegetative light, I am going to need about 400 W of light for my mothers to keep them vegging and about 200 watts of light for my clones. What I would do is buy a 400W metal halide for my mother plants (you could put at least 3 or 4 moms under this light). I would buy three, 2-bulb, shop lights for my clones (That will be 240 watts of fluorescent light).

The picture below summarizes my calculations above. Keep in mind that with flowering and vegging going on in the same room (different light cycles) you will need to keep those plants separate. I would put the moms and clones in little cabinets to keep them separate from the flowering operation.

You will need a lot of other things for this set up like fans, filters, etc., but the purpose of this article is to help you size your lights.

As you gain more experience, you could do a lot better than 4 ounces per month with this set up

Section 8 – Conclusion
I started writing this as a little post. As I got into it, I realized more detail was necessary. I offer this article up for review and comment. I am sure there will be some growers more experienced than myself that will disagree with some or all of this. I encourage intelligent comments and recommendations.

I hope this helps.
Small Potatoes

Let's help each other, by spreading our knowledge of the plants we love
Scroll up

0 Members and 14 Guests are online.

guest counter
Today were 188 (yesterday 523) guests online.

Board Statistics
The forum has 1231 topics and 21953 posts.

0 members have been online today: