A Complete Guide to Cannabis Hydroponics

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Over the years, cannabis cultivators have experimented with various growing methods. One of the most effective techniques is hydroponics, which has gained popularity due to its many benefits. Instead of using soil, hydroponics relies on nutrient-rich water to grow cannabis.

To give you an idea of the success of hydroponic setups, the Institute of Environmental Science and Research conducted research using indoor hydroponics on 18 plants. During the study, scientists achieved a successful cycle of 31.1 oz of dry female flowering heads per plant using indoor hydroponics.

If you’re looking for the same success with your own marijuana plants, our hydroponic growing guide has all the details you need to get started. Find out how to grow your cannabis with various hydroponic systems, the nutrients you need, and how to protect your plants in our beginner’s guide below.

Benefits of Cannabis Hydroponics

Hydroponic cannabis cultivation gives you several advantages over traditional soil-based growing methods, such as:

Hydroponic cannabis growth is 30% to 50% faster compared to soil-based methods.
Different types of hydroponic systems can produce larger yields if done correctly.
Nutrients in a hydroponic system are more readily available to your marijuana plants.
You can control nutrient levels easily.
Regulate your plants’ growing conditions without struggling with the elements.
With hydroponic techniques, you can control vegetative and flowering stages.
Since you’re growing cannabis without soil, you’ll have a cleaner environment, and you won’t have to clean up your floors or drag bags of soil around.
With the right hydroponic setup, you’ll experience fewer pest infestations and diseases, especially if you have indoor grow systems.

Hydroponic Systems for Growing Cannabis

There are a variety of hydroponic systems, and it’s important to choose the right one if you’re a beginner. There are two types of cannabis hydroponic techniques you can choose from: active and passive. The difference between these two systems is the way they’re designed.

Growing Cannabis with a Passive Hydroponic Procedure

With a passive hydroponic cannabis growing system, you get a more streamlined design. It uses a low-tech method that can give your marijuana plants the water and nutrients they need with capillary action instead of electricity. The system relies mostly on evaporation and gravity to circulate hydroponic nutrients to cannabis plants.

There are two types of passive hydroponic systems:

Wick system: Absorbent wicks draw nutrient-rich water from a reservoir into the growing medium. The constant moisture delivery keeps the roots hydrated and fed without the need for pumps or electricity.
Kratky method: You can suspend plant roots above a nutrient solution and leave an air gap that provides oxygen as the water level drops. As the plant absorbs the solution, it naturally creates space for root aeration.

Passive methods for cannabis are inexpensive, and it’s easy to set up, which means it’s the best hydroponic system to use if you’re a beginner.

Growing Cannabis with an Active Hydroponic System

An active hydroponic system uses electric pumps and oxygenation of water with airstones to move nutrients. You can use electronic devices with this system to feed your cannabis plants the right amount of nutrients and water, which can reduce your workload.

Furthermore, there are different types of active hydroponic procedures, such as:

Ebb and flow system
Drip system
Aeroponics
Deep water culture
Nutrient film technique (NFT)

There are many benefits when using active hydroponic cannabis cultivation, like water efficiency, and you can provide plenty of oxygen to your cannabis plants.

What You’ll Need for a Cannabis Hydroponic Setup

A handful of cannabis seeds piled on a white table

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There are a few items you’ll need to make the hydroponic process easier and successful. If you’re going for a DIY hydroponic system, you’ll need the following to get started:

Your chosen seed to harvest
HPS or LED grow lights
Grow tent
Hydroponic reservoir and tray
A growing medium
Airstone and pump
Net mesh planters
A ventilation fan and ducting tubes
Carbon filter
Oscillating fan
pH and TDS or ES meters
A hygrometer or a thermometer

With this list of items, you can create a basic indoor hydroponic system for your plants.

Steps to Growing Cannabis with Hydroponics

Growing cannabis with hydroponics can be tricky at first. For example, nutrient lockout can affect cannabis growth, so it’s important to learn how to prevent that from happening. Read our complete cannabis growing guide using hydroponics below so you can yield a successful harvest the first time around.

Select a Growing Medium for Cannabis

The first step to growing marijuana without soil is to select a hydroponic medium that will work for you. Mediums are substances that will hold the intersection of the stem and root in place. The roots of the cannabis plant will then grow down into the water to search for nutrients.

The method of growing cannabis depends on the materials you use:

Coco coir: The medium is used to grow hydroponic cannabis with fiber from coconuts, which allows for excellent water retention. It also prevents root infections because of its plant-stimulating hormones.
Pebbles: Growing cannabis using pebbles is the best for aerating roots. With clay pebbles, you may have to adjust pH levels to optimize the cannabis growing environment.
Perlite: This is a type of volcanic glass that expands when it’s exposed to high temperatures. The medium is sometimes used in garden soils to prevent aeration, so it’s ideal for cultivating cannabis hydroponically.
Rockwool: A substance that’s manufactured using volcanic rock. It has a wool-like texture and is ideal for retaining water. This medium is good for keeping cannabis roots hydrated and can be used throughout the total grow cycle.

Control Your Grow Room Environment

For the best results, you will need a grow space like a room or a tent to give you more control over your environment. With a room or tent, you can control the temperatures and ensure no heat or light is lost when you grow hydroponic cannabis indoors.

Consider the temperatures with hydroponically grown cannabis. The cannabis grow cycle requires fairly warm environments, so during the day, make sure your grow room is at 72 or 76 degrees Fahrenheit when the lights are on. Then lower the temperatures to around 67 degrees Fahrenheit when the lights are off.

Adjust Your pH, EC, and Humidity Levels

Growing plants with hydroponics can become labor-intensive because the changing needs must be adjusted as your cannabis plants mature. pH, humidity, and EC must be adjusted, especially when the plants start to flower. The pH levels and nutrient concentration, such as EC, should increase slightly as the plant ages.

The nutrient density should be increased in small amounts each week in your hydroponics system. When your cannabis plants mature, nutrient levels should decrease a few weeks before harvest. Furthermore, make sure young cannabis plants have a humidity level of 60%. Then, when the plants start flowering, lower the humidity to 40%.

Hydroponics is a soilless method, so you’ll need a hydrometer to measure the room’s ambient humidity to ensure you have the optimal environment when growing with hydroponics.

Use the Right Hydroponic Growing Setup

Hydroponic cannabis cultivation will be easier when you choose the right growing setup. The Kratky setup is a passive method of growing plants, and it’s more affordable. You can use buckets or baskets for this method. Place cannabis plants in net cups and insert them into a lid. Over time, the roots will grow down into the nutrient solution below.

You can also use a deep water culture method when you grow the marijuana indoors, which uses a single reservoir that’s filled with nutrient solution. Plants are placed in net cups and then in holes of Styrofoam sheets that float on top of the water.

There are other popular hydroponic methods or systems, such as the nutrient film technique (NFT), drip system, or wick option. All these hydroponic methods for cannabis use different materials and provide various ways of growing your plants, so it’s important to choose the right one based on your budget and time.

How to Start Your Cannabis Plant

You can grow seeds quite easily because they need very little in the beginning stages. When your cannabis seeds are young, they need less intense growth lights and hydroponic nutrient solutions. Additionally, some cultivators choose to give their cannabis plants nutrients when they’re bigger.

Consider diluting your nutrients to 10% of the regular concentration to prevent damaging your cannabis roots. Wait for your plants to have a more stable root system and bigger leaves before giving them an increase in nutrient solution for high-quality cannabis plants.

What to Do While Your Hydroponic Cannabis is Growing

One of the most difficult parts of growing cannabis hydroponically is that its weekly requirements change. For example, changing hydroponic water must be done every 14 to 30 days, even if you don’t see any issues.

If you don’t change your water, you could experience problems with algae, biofilm, or inaccurate pH levels. You will then need to remove biofilm or algae because it can deplete oxygen levels. A pro tip is to keep detailed logs when growing with hydroponics so you can keep track of how much light, nutrients, and pH levels your plants need. If problems arise, you can then pinpoint where they started.

Ways to Flower Your Cannabis Plant

If you’re growing cannabis hydroponically indoors, you need to prompt the flowering stage. Hydroponic cannabis cultivation requires strict lighting adjustments. When your cannabis plants start to bloom, give them 12 hours of light and 12 hours of complete darkness.

No matter what popular hydroponic methods you’re using, light leaks can impact how your cannabis plant flowers. During the 12/12 lighting, start giving them a flower nutrient formula for the first month of the flowering stage.

Watch out for biofilm and mineral blockages. If problems arise, you can use Clear Flow™ to combat nutrient lockout on your cannabis roots.

Common Questions About Cannabis Hydroponics

Is Hydroponic Growing Better for Cannabis?

Hydroponics is a method that’s better than using soil because it gives you a direct method for supplying nutrients to your plants. The many different types of hydroponic systems can provide optimal oxygen and water to your plants’ roots. What’s more, hydroponic plant growth is faster compared to growing in soil.

How Often Should I Water Hydroponic Cannabis?

Growing cannabis without soil means that the frequency of watering plants changes. It also depends on which hydroponic system you’ve chosen and the size of the container. For example, with coco coir, you’ll need little irrigation. Use 10% to 15% of the pot’s capacity to water the plant so it can dry faster, and then irrigate with the same amount of water a day.

If you experience any problems with your watering system, keep your hydroponic garden safe with Clear Zona™, which is an irrigation cleanser to prevent mineral buildup and biofilm. It’s safe to use throughout the stages of cannabis plant growth to improve water clarity.

EPM is Here To Help You Protect Your Hydroponic Cannabis Plants

There are many advantages of hydroponics, especially when growing cannabis. However, problems can also arise with your irrigation system and when your cannabis plants start to grow. Clear Flow and Clear Zona give you simple solutions to keep your hydroponic system clean.

With Clear Flow and Clear Zona, you can prevent biofilm and the buildup of green water, so your cannabis plants can fully absorb the nutrients they need without interruption.

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