Lighting and its importance in cannabis growth

Light is needed for photosynthesis and photosynthesis is needed to grow big, healthy marijuana buds. Photosynthesis is the natural process where cannabis plants use light energy and convert it into chemical energy in the form of sugars. Your weed plants will use carbon dioxide, water, and the energy from photosynthesis to synthesize all of that into sugars the marijuana plants can use. The photosynthesis process starts with your cannabis absorbing light energy by plant proteins containing chlorophyll.

What type of lights are used for growing cannabis?

There are two different kinds of grow lights needed for marijuana cultivation: 1) Compact Fluorescent Lights (CFL) and 2) High Pressure Sodium (HPS) lights. Compact fluorescents are only used for very young cannabis plants such as clones or cuttings in a clone tray tray waiting to root. HPS lighting will be used once your cannabis clones have rooted and are already transplanted into your grow pots. As a marijuana grower, you will be relying on HPS lighting for both the vegetative and flowering stages of growth for your cannabis plants.

How does the duration and intensity of your lighting affect your marijuana plants?

As an indoor grower you will need to manipulate the light cycle in from 18 hours to 12 hours when you transition from vegetative phase to the flowering phase for your marijuana girls. This actually mimics what happens in nature except maybe it’s a little bit more abrupt since we are kind of forcing the plants into flowering. When growing cannabis outdoors, your marijuana plants will start to bud or flower a month or two after the summer solstice. Light is essential to the photosynthesis process in that the more light equals bigger buds. A marijuana grower will need to give a sufficient intensity of light to give their plants enough light energy to produce some killer cannabis flowers. If you do not have enough light, you may create stress for your weed plants and they may not produce any decent marijuana buds for you.

 How far away do my lights have to be from my cannabis plants?

If your lights are too powerful and too close to your plants, you will end up burning your cannabis. As a general rule of thumb with HPS lighting, a marijuana grower does not want the HPS bulbs to be closer than distance of your elbow to the tip of your finger. You need to keep your HPS lights a safe distance from the top of your cannabis plants. You will constantly want to adjust your lights as your marijuana plants grow taller so it is recommended to use adjustable pulleys. You want no less than 18 inches from a 600 watt HPS bulb to the top of your plants and you will need a little more distance for higher powered bulbs.. If the leaves on your marijuana are yellow, curling up, and getting crispy, then you are most likely burning your cannabis so you need to raise your lights pronto.

What type of lights should I use for my cannabis clones?

At the beginning of your grow, you will be starting with either from seeds or clones that you mau have purchased from a cannabis dispensary. If you are an advanced marijuana grower, then you may be doing your own cannabis clones from mothers that are in constant vegetative phase of growth. Young cannabis plants in this growth stage should not use any lighting that is more powerful than compact fluorescent or T5.  Do not use HPS lighting for marijuana plants in this early stage of growth or you will certainly fry them!  You need to wait a little bit until your cannabis clones have rooted and are ready to be transplanted in your grow pots.



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Use HPS lighting for your cannabis plants in both veg and flower growth phases!

When your cannabis plants are in vegetative stage this means that they have 18 hours of light on them every 24 hours.  the amount of photons that you’re  marijuana plant will receive will determine how big and strong and ginormous, but he will get at the end of your Harvest. We recommend that you use high pressure sodium lights during the beginning of the vegetative stage when  a grower transplants his are hard clones into growing pots that they are going to use for their Harvest.

General marijuana growing rule related to the light spectrum: blue for veg and red for flower

Cannabis plants will use a lot of the blue spectrum from the visible light spectrum during the vegetative stage of growth. The 18 hours of light will really help the plants to grow thicker and taller which is what you want to see prior to going into flowering. It is in this stage of growth that a marijuana growers should be using an advanced growing technique called topping. Topping is basically pinching off the top node of a cannabis plant so two new nodes will emerge in it’s place.  The vegetative stage for indoor marijuana growers will usually last anywhere from two to four weeks.

Once marijuana plants enter the flowering phase, they will require more red light out of the visible light spectrum as opposed to the blue that they were using in the vegetative phase. The marijuana grower is also cutting the amount of light shining on your marijuana plants by cutting the light cycle down from 18 hours to 12 hours during flowering. This will force your cannabis plants go into flowering mode and buds will start setting up. You will also be using HPS lighting during this cannabis growth stage. You should be aware that yuour cannabis plants will tend to stretch for the first week or two in the flowering phase. The plants will slow down with the rate of vertical growth after that final stretch.

Tip for your marijuana grow room: More light energy = bigger buds

The more light you put on your cannabis, the bigger your marijuana buds will grow. This is true as long as you are not burning your weed plants. Many cannabis growers will use reflective material such as Mylar coating on the sides of their grow room. This allows light energy to bounce off the sides of your grow room and this will maximize the amount of light shining down on their cannabis plants.


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Safety for marijuana growers using HPS lighting

I wanted to give a word of caution and safety regarding HPS lighting systems to aspiring marijuana growers. HPS lighting will require three things to set up: 1) the HPS lights, 2) the ballast that will be powering the bulbs, and 3) the lighting controller that will be powering the ballasts. Ballasts will generate heat so it is recommended that you keep your ballast out of your grow room if you can when you are setting up your lighting. The lighting controller will need 240 volts to power it. If you are not comfortable installing a 240 circuit into your panel, then you should hire an electrician! Another word of caution is that you do not leave any electrical cords on the ground as your grow room will have water and water with electricity is a great combo for a disaster waiting to happen.

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