What is Hydroponic Weed? [Beginner’s Guide]

Every beginner grower needs to know this

The term ‘hydroponics’ is a Latin term that translates to ‘water working.’ In terms of growing weed, it relates to the process of growing the plants in highly oxygenated water that is also enriched with additional nutrients. In basic terms, hydroponic marijuana is cannabis that is grown without soil. There are several ways to grow weed hydroponically. You can suspend the roots of your plants in Rockwool, clay pellets, water, coco peat, sand, or gravel.

Regardless of what you use as a growing medium instead of soil, you have to apply a nutrient-laden solution to the roots. The water that isn’t absorbed by the roots gets recycled through the system and is absorbed later.

A Brief History of Hydroponics

The Hanging Gardens of Babylon was one of the Ancient World’s Seven Wonders. Theories of where and when they were grown vary from being created by Babylonian King Nebuchadnezzar II in the early 6th century BC to being built by Assyrian King Sennacherib in the early 7th century BC in Nineveh. Regardless, it is believed that the gardens were created using hydroponic methods. It is also likely that the Aztecs used hydroponic techniques at Lake Tenochtitlan in the 10th century AD.

In the modern era, this form of growth has helped create some of the world’s best marijuana strains. As cannabis cultivation has increased, improvements in hydroponics have emerged. Although there are many different forms, several of which we look at below, hydroponics is ostensibly the practice of using soilless systems to grow plants.


All hydroponic systems must provide oxygen, water, and a host of nutrients to marijuana plants. Nutrients include:

  • Nitrogen
  • Phosphorus
  • Potassium
  • Calcium
  • Magnesium
  • Sulfur
  • Iron
  • Chlorine
  • Manganese
  • Boron
  • Zinc
  • Copper

Nitrogen, Phosphorus, and Potassium are by far the most important nutrients, however, and most solutions contain 15% of each; also known as a 15-15-15 solution. If you are growing weed in temperatures below 80 degrees Fahrenheit, you need higher amounts of nitrogen. Other possible solutions include 20-20-20 or 23-19-17.

During the flowering process, increase the level of Potassium so that it comprises at least 20% of a solution. Be wary when fertilizing the plants, because too much kills them while too little slows growth. When your reservoir’s water level gets low, add tap water that has been aged at least three days. It is also a good idea to change the nutrient solution every two weeks and use hot water to clean out all the equipment you use, especially the pumps and reservoir.

Types of Hydroponic Systems


This is a unique method because you don’t use a growing medium. Most growers tend to use a tiny amount to root a cutting or germinate the seed, however. The roots of the marijuana plant are suspended mid-air inside a chamber that is kept at 100% humidity. You must use a fine spray filled with nutrients.

This form of feeding enables the roots to absorb large amounts of oxygen. As a result, the plant can grow up to 10 times faster than it would in soil, with practically no water loss through evaporation. If you use this method, be wary of clogged misting valves as it could prevent moisture from getting to the roots; this will kill your plants.

Deep Water Culture (DWC)

This is one of the most straightforward hydroponic systems to use, which makes it ideal for beginner growers. All you have to do is put the plants in separate containers and place each one in a grow tray that gets suspended in water. Your water tank will have an air pump that ensures the water remains oxygenated, and you add nutrients to the water to feed the roots. Although the roots are submerged in water, the oxygenated air pumps ensure they receive ample oxygen.

Drip Irrigation

This is a popular commercial option because it saves a lot of water. You need to place small droppers beside the roots of the plant, which are in pots containing the growing medium. Little drops of this nutrient system drip out regularly and feed the plant. It offers a low level of evaporation and, as it is silent, it is perfect for a clandestine operation to keep your grow area protected from thieves.

Ebb & Flow

This is different to several hydroponics systems because it does not involve the continuous submersion of the roots in water. It works similarly to an ocean tide, as it fills a tray with oxygenated water and treats the plants and growing medium. When it is full, the pump switches off, and the solutions drain back down into the reservoir. It stays there until you are ready to flood the garden again.

Nutrient Film Technique (NFT)

NFT is a complex system and involves pumping your water solution from the reservoir to your planting tube. Using large PVC tubing angled at a slight decline is used commonly. This tactic ensures that, when the water drains down the tube, it passes by the roots of all marijuana plants before it gets recycled in the container.

One of the most significant problems with this system is that the water solution could fail to leave the tube, stagnate in the channel, and kill your plants. This is why you need to make sure the tube is cut at a steep enough angle to allow for easy passage of the water.

Wick System

This is another easy-to-use system. It works like a DWC system insofar as it uses a material such as a length of rope through a PVC tube. You pull the solution up the line and place it in the tray. With the wick system, you don’t need to bring the water to the plants. Although it may not result in plants that grow as quickly as they would with more complex systems, it is the ideal way to learn hydroponics through practice.

What are the Most Common Hydroponics Growing Mediums?

While there is a wide range of growing mediums, three of them stand out. Please note that each option varies in its ability to retain water and allow oxygen in.

Clay Pellets

Although they are light enough to work with easily, clay pellets are still sturdy enough to support marijuana plants – and they are reusable! They wick moisture up to the roots and enable oxygen to flow through due to the size.


This medium is popular because it retains moisture exceptionally well. It consists of thin rock fibers developed by heating rock to very high temperatures and spinning them into tiny threads. If you purchase Rockwool as a hydroponic growing medium, soak it in a solution with a pH of 5.5 for up to 12 hours. Make sure its pH is between 5.5 and 6 before use.

Coconut Fiber

This is a more environmentally-friendly option than Rockwool because these fibers come from waste products. As well as retaining moisture and allowing in more oxygen than Rockwool, coconut fibers contain hormones that keep infection and disease at bay.

The Pros & Cons of Hydroponics


  • It allows for higher yields from smaller growth areas.
  • Almost total control over the growing process, which typically means better quality cannabis.
  • Weed grown using hydroponics matures faster, and experienced growers can complete six crops in a single year.
  • As there is no soil involved, you don’t have to worry about a myriad of pests, which means no need to use pesticides.
  • Assuming you monitor everything correctly, there is a lower risk of water stress than with crops grown in soil.
  • As you have full control, you can even tailor feeding schedules to the needs of a specific plant.


  • You won’t get your hands on a decent quality system for mere pennies. If you are a recreational grower, this kind of system is probably more trouble than it’s worth financially.
  • Although you reduce exposure to disease, there is a unique danger associated with waterborne plant diseases. They spread incredibly quickly and are extremely difficult to remove.
  • Barring the Wick and DWC systems, it is a complicated process which requires knowledge and patience.

Final Thoughts on Hydroponic Marijuana

There is a lot to like about hydroponic marijuana. It enables you to grow a lot more weed per annum, and you only need a relatively small growing area to get started. It lets you grow high-quality cannabis in areas where you usually can’t grow in soil. There are fewer pests, and the overall quality of well-produced hydroponic weed is exceptional.

However, it is a tough skill to master, and the initial set-up costs are considerable. If you fail to keep the grow area wholly sanitized, your entire crop could succumb to disease in double-quick time. It is not something you can learn overnight, but if you have the time, money, and patience, learning how to grow weed in this way could yield tremendous dividends. However, I don’t recommend it for recreational growers, as it works best when growing large amounts.

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