Hydroponic Cannabis- A Guide on Hydroponic Grow Room Setup

I introduced you to the hydroponic system of growing cannabis where we understood the drip line system, the nutrients required, the measuring instruments, and more. In this article, we take the process a notch ahead and tell you all about the hydroponic grow room setup which includes lighting, seed germination, grow room condition, vegetative phase and the flowering phase.

Let’s start with the very essential part of the hydroponic system- the lighting. 

Hydroponic Grow Room Setup-Marijuana Lighting

To make sure your cannabis plant grows accurately and completely, you have to be cautious about the light they need. Lighting is an important part of the Hydroponic Grow Room Setup. From blue wavelength to the red and orange one, I will walk you through how these are used at the different growing stages. But, before that, why do we need the light? 

Yeah, you guessed it right! Photosynthesis. 

We gave the plant all kinds of nutrients, but the light is important to convert them into plant food. 

Light cycle timing is a very crucial matter when it comes to growing marijuana, where it is cannabis Indica or Sativa. The light cycle timing triggers the needed growing responses, which is different at the vegetative and flowering phase light cycle. 

Let's see our options and understand which suits our plant's development the best!

Since the beginning of the modern hydroponic system, people have been using the HID (High-Intensity Discharge) which consists of HPS (High-Pressure Sodium) and MHL(Metal Halide Lights). LED has been a recent development in the lighting field. 

Metal Halide lights come the closest to the regular light and are preferred for the vegetative phase of the plant due to the blue wavelength of light produced. It promotes bushy and compact growth and is, therefore, better for the early stage of growth. 

On the other hand, HPS emit light on the orange and red end of the spectrum and a small amount of blue, and therefore more preferable during the bud formation and flowering stage. 

Okay, you better start writing this, before you're lost. 

HID light provides the most accurate environment for the plant to nurture, but there is a catch. They require great energy in the form of heat, which leads to the need for a ventilation system. Moreover, HID lamps also need a ballast, so you need to invest in that too. 

Now that you understand the drawbacks faced by HID lightings, you would understand the shift towards LED lights. 

LED lights are preferred because they give you better control and use less amount of energy than what is required for HID Lamps. You can use LED lights during all stages of development as they provide a spectrum for every phase. Moreover, they don't require additional investment in the form of ballast and don't present any heat and space issues. 

There is another type of light used for Marijuana Cultivation; Compact Fluorescent Lamps, also known as CFL. They don't produce as much heat as the HID lights, which allows them to be placed closer to the plants. Usually used to compensate for the blue light during the vegetative growth, CFL is now available in different spectrums. 

Out of all the mentioned lights, LED takes away the prize with its measure benefits and great value.

Now that we have established LED the King of Cannabis Lighting, let's move forward. 

Hydroponic Grow Room Setup-Grow Light Timing

Marijuana plants start vegetating during spring when it is neither too hot nor too cold. The kind of light that is fed to these plants will dictate their growing process. 

During the vegetative period of the plant, the light should be turned on for 16-24 hours, leaving the plant in darkness for 0-6 hours. 

LED lights are considered best for this process, as the HPS lights are not so active in a blue/green part of the spectrum and hence, not very useful. As for the MH light, they emit quite a great deal of heat which is not a suitable condition for the marijuana plants to grow in. (Since they start growing in spring)

When they reach the flowering stage, we need to change the light cycle to 12 hours of light and 12 hours of darkness. This would be enough to trigger the flowering phase. You can start doing this once your plant reaches 12-20 inches of height. 

Once the required conditions are set for flowering, you will notice the change in 1-2 weeks. Another note for all you cultivators; Make sure you get rid of the male plants, as they only create pollen which will impregnate the female plants with seeds. Nobody likes a seedy weed!

Hydroponic Grow Room Setup-Marijuana Seeds and Clone

Before we dive into this, you can get Marijuana seeds from a friend who grows weed, or if you ever found them in your buds. But there are a few things you need to know before making the purchase.

Let's start with the type of marijuana strains- Sativa and Indica. If you're a cannabis enthusiast, chances are, you have already heard of them. They both have different characteristics, yield, growth, physical features, strength, and required growing conditions. 

The Cannabis Sativa is largely recognised as the original strain of Marijuana, came to us from the Asian, American, and African lands. They are pretty similar in characteristics, with a few alterations here and there. 

Sativa plants are usually tall with long, narrow fan leaves. Their buds are loosely tied when compared to Indica, and they grow faster than them. Enriched with a sweet and fruity flavour, Sativa strains are extremely potent with a high amount of THC giving you the energetic high. If you're not a fan of strong aroma, Sativa is an ideal breed to grow.

Coming to Indica strain, they originated in India, and are bushy with closely packed buds with compact roots, making them a favourite for the indoor growers. Its leaves are distributed with a high concentration of chlorophyll, lending them a darker or almost purple strain, which also allows them to process the light much better. This further assists in faster growth and bud production. 

Talking about the cannabinoids, they have a very high THC-CBD ratio and a much more strong and powerful punch than Sativa.

Now, that the confusion between the strains is cleared out, let's look at the seeds. 

With the modern hydroponic system, there has been an evolution in the field of seeds too. One of the most impressive things that I came across was "auto-flowering seeds". These are a boon for hydroponic growers who have to invest in different lighting to trigger the flowering phase. But with auto-flowering seeds, they commence their flowering phase as soon as they reach maturity, which starts only after 3 weeks.

This nullifies the need to have a separate room for vegetative and flowering phase, allowing you to grow plants of different ages together. 

Moving forward, I had previously mentioned that male buds aren't very desirable when growing weed. For beginners, it may become really tough to differentiate between them and then pluck them out. For this, we have feminine seeds!

These, obviously, produce only the female buds, with great growth and quality. You might think that the potency of the weed may get compromised, but that's not the case. In fact, the end flavour and potency is better than the weed produced from non-feminized seeds.

There are two more types of seeds you need to know to master hydroponic growing systems- indoor and outdoor seeds. Their names are self-explanatory, but it also depends on the growing condition they require. For eg, a strain that is grown in the humid region will require high humidity and temperature. If you don't have that kind of condition outside, you will have to replicate it inside. 

| Also Read: Hydroponic Cannabis: How to Grow Hydroponic Marijuana? |

Hydroponic Grow Room Setup-How to germinate the seeds?

If you're using clones, you can skip this session and jump to the next one. For those who are using seeds, let's have a look at the germination process. 

Before you start with this process, make sure your Hydroponic Grow Room Setup is complete and working. 

Germinating seeds hydroponically requires a medium which is used to support the roots. They do not provide any nutrients to the plant as that is done by the nutrient solution. 

A medium can be of different types and is essentially a substitute for soil. I personally use Rockwool, but you can have your pick. 

For germinating your marijuana seeds, surround it with the medium, and place it in the water. Only the bottom 70% should be submerged while the top part along with the seed stays above. Once your seed germinates and has a root that is about 1/8 of an inch long, you can take the seed and place it, root down, on the growing medium in your hydroponic garden. (germinating is illegal in th UK - This is for educational purposes)

Hydroponic Grow Room Setup-Vegetative phase of marijuana growth

Once you're done with seed germination, your marijuana plant will start with its vegetative phase. During this phase, your plant will set a strong root system along with fully developed leaves for photosynthesis. This is also the preparation stage which leads to the flowering stage. 

During this phase, your weed required 18-24 hours of daylight for adequate growth and photosynthesis. You may want to start with placing the lights at least 20 inches above the top of the plant to avoid drying out the leaves. You can then gradually reduce the distance until you get to the desired distance. 

The vegetative growth is said to last for 2-4 weeks depending upon the energy produced by the plant. The growth of the plant is related to the leaves size and photosynthesis system. Bigger the leaves, better the photosynthesis system. Better the photosynthesis system, faster the growth. In an ideal condition, your plant can also grow up to 6 inches per day.

During the vegetative phase, you will notice a change in the leaves, as the number of blades will start to decline, and the gap between two sets of leaves will reduce. What's important for proper growth during this phase is the proper lighting and adequate room conditions. 

Light for the vegetative phase

Your Hydroponic Grow Room Setup requires the right kind of lighting for the complete and proper growth of your weed. Vegetative phase demands that 14% of the light should be blue light which helps to limit the stretching. 

HPS lamps emit 4-6% of blue light, which is not enough and may result in a weak plant with long space between branches. You can either use full-spectrum LED light or MH lamps. 

Another new invention is the Ceramide Metal Halide lamps, which provide a larger range of a spectrum than MH.

There are also CFL lamps, but they are not as efficient as others.

We know that they need 18 to 24 hours of light per day during this phase, but it is recommended to use a timer for less than 24 hours. The lighting need depends on several factors like the temperature of the room, reflectivity, spacing, maturity of the plant, the distance between the plants and lamp, and the performance of the lamps, etc. 

You will need 50 watts of power per square foot unless you're using LED lamps, which use much less energy. Additionally, you can also coat the wall with something reflective that is not directed toward the plants.

Hydroponic Grow Room Setup- The condition

The temperature of your hydroponic garden should be maintained for the proper germination and growth of your weed. The usual temperature range that is accepted by the plants is from 60 degrees to 92 degrees Fahrenheit, but we take the most ideal temperature to be between 70 to 83 degrees.

The idea is to keep the temperature on the higher side when the plants are using the CO2, while on the other hand, we can keep the temperature on the lower side at night. I would suggest, and this worked well for me, to keep the temperature between 72 and 77 degrees during the entire growth period.

Now let's see how ventilated your garden should be. 

Plants use CO2 and light for photosynthesis, and the heat is given out from the lamps. You need to have a good ventilation system to bring in the CO2 rich air while taking out the CO2 depleted air. 

Having an extraction fan on the ceiling promotes the airflow. You have to keep in mind that your fan should change the air in your garden at least every five minutes. Of course, this largely depends on the size of the room and the power of the fan. 

I have homies who use oscillating fans instead of an extraction fan, especially during the flowering phase. Since the tightly packed buds are prone to moulding, a fan helps to avoid that. 

Another benefit of using an oscillating fan is that it helps to straighten out your plant's stem and avoids having fragile plants. In the natural world, when the plants are bent by the wind, they develop small fissures which are eventually replaced with scar tissue, lending them the woody and strong characteristic. 

We have one more aspect of ventilation to cover before we move to the flowering stage. Many a time, the hydroponic garden may not have any walls where the vents can be fitted. In this case, the air needs to be moved a long way, which is done through ducting. 

Ducting isn't as tedious as you might think since the standardized size fits almost every fan. You just have to be careful of too many twists and turns, as it hampers the efficiency of your ventilation system.

If you're someone who is really enthusiastic and ready to spend big bucks, you can also augment the CO2 supply. Fresh air contains around 390 PPM of CO2, but your Marijuana plant can handle 1500-2000 PPM. 

The easiest way to do it is to get the CO2 bottles and kit from the store and use the timer to regulate the flow. You can run the CO2 through the pipes with tiny holes above your plants. Since CO2 is heavier than air, it will fall on your plants. Just make sure to set the timers in such a way that the CO2 flow turns on when the fans are turned off.

A cheaper way to go about the process would be to use a mixture of baking soda and vinegar or dry ice. Just remember not to use fumes from a propane heater as they contain some dangerous gasses and can cause a fire hazard.

Hydroponic Grow Room Setup- switching to flowering (budding)

There is no correct answer to the question- when to switch to flowering. 

You switch to the flowering stage by changing the lightning to 12 hours of light and 12 hours of darkness. 

I have a buddy who waits for 3-4 months before changing the cycle, while I only do it within a few weeks. It depends on what you desire from your plant. A longer waiting period creates monster plants while a shorter one leads to smaller plants with a single bud. 

The height of your plant will continue to grow even when you shift to the flowering stage. The growth depends upon your strain- Indica will double in height, and the Sativa will triple. You can use this method to decide when to end the vegetative phase by taking the height of your hydroponic garden and lamps into consideration. 

If you're using auto-flowering seeds, they will shift to the flowering phase whenever they are mature enough, regardless of the light cycle.

Flowering phase

You have to understand why the flowering stage is so crucial. It is the time where all your "high" ingredients are produced by the plant. All the THC, CBD, and CBN is the work of the flowering phase. This means your flowering phase will decide the potency of your strain. 

You may notice that your plant grows slower in the flowering stage. This is because energy is utilized for the flowering process. You have to make sure that your plant is at least 6 inches tall and has a minimum of four sets of leaves before moving on to the flowering stage.

The lightning for the flowering stage has already been discussed, but you have to ensure that the 12 hours of darkness is perfect without any interruptions from daylight, room light, or any other light. Imperfect lightning, other than moonlight, delays the flowering process, and if it continues, can hamper the flowering stage completely.

The presence of tiny white hairs at the bud sites is the indication that the flowering has begun. They are visible after 10-14 days after you initiate the flowering stage. Now it is time to remove male plants if you have any.

These tiny white hairs will, after some time, become the red or the white hairs that will turn into big nice buds.

Depending on the strain, the flowering phase usually lasts somewhere around two months or a bit longer. This means that you’ll need between 3 and 4 months from seed to harvest with a hydroponic system.

This was all about the hydroponic grow room setup that is required during the vegetative and flowering phase. We will be talking about harvesting, drying, curing, & storing weed in our next article. Stay tuned for it. 

| Also Read: Hydroponic Cannabis: How to Harvest, Dry, Cure, & Store Weed|

If you’ve any questions or doubts, feel free to comment below.