Hydroponic systems are the future of agriculture. Deep water cultures are the purest form of hydroponic farming. While deep water cultures are simple to set up, you’ll have to learn some basics before getting your farm started.
In this article, we’re going to explain everything you need to know before establishing your deep water culture system. Let’s dive in.
Before diving into all the details about deep water culture, there are some basics about farming and hydroponics that we must catch up on in order to have a full understanding of deep water cultures.
Regular agriculture depends primarily on treating the soil with nutrients while supplying them with plenty of air. There are also fertilizers and pest repellents added to the soil to make it a semi-controlled environment.
Earth’s soil is a great natural resource for farming and growing. However, they’re riddled with problems. For example, traditional agricultural methods are tedious and take a lot of time to get the soil ready.
If we exclude some of the most perfect soils of the planet, the vast majority of soil contains large amounts of clay and sand. Additionally, there are a lot of creatures that live in the soil, including worms and bacteria.
All these elements compete with the plant for water and minerals, limiting the plants’ chances of reaching their full potential, and wasting a lot of money on fertilizers and pesticides to overcome these issues.
Another main issue that hydroponic cultures solved is the availability of water. In regular agriculture, if you don’t water the plant adequately, the roots in the soil will get dehydrated.
Depleting the roots of moisture disrupts the water cycle inside the plants, which consequently affect the rest of the plant, causing wilting.
One the other side, overflowing the plants with water can severely obstruct and cut off the oxygen supply to the roots, which is known as plant flooding or suffocation. This can irreversibly damage the plant and cause the decaying of plant roots.
Plants’ life cycle and growth rely mainly on a process called Photosynthesis. This process is performed by all kinds of green plants, algae, and some microorganisms.
In this process, a certain chemical inside the plant, known as chlorophyll, is responsible for absorbing sunlight. Along with minerals, water, and carbon dioxide gas, plants use them to make their own nutrients, which is glucose sugar.
As you can see, the soil wasn’t required anywhere in this process. This means that plants can be grown in a culture without including soil in the process, provided that plants get their adequate levels of sunlight, water, minerals, and air circulation.
This type of farming is known as a hydroponic system. In this method of plants growing, the plants are grown over chemically inert mediums or carriers with pores in them, such as gravel, clay pebbles, rock wool, perlite, or vermiculite.
These carriers are used to replace the soil, in which a concoction of water, salts, and nutrients are transported from a separate reservoir to the roots through the capillary action of the plants.
What Is Deep Water Culture?
Deep water culture is one of the most popular hydroponic systems. In this plant production method, the plant’s roots are suspended in a solution of highly oxygenated water containing different types of nutrients.
This method is also known as floating systems or raft systems, as the carrier medium looks like a raft in a pool of treated solutions. These pools are usually about 1 foot in-depth, where the plant fitted on these rafts and their roots submerged under the water’s surface.
Deep Water Culture System Nomenclature
A major part of understanding what deep water culture systems are comes from understanding its name. So let’s have a better grasp of its nomenclature.
To understand why it’s called deep water culture, we have to break down the full name into its words.
Let’s start with “water”. As we discussed earlier, while the soil isn’t crucial for plants to grow, they still require water so that they can carry out the photosynthesis process and make their own food.
A deep water culture system is characterized by having a large water tank in its constitution. This tank is usually referred to as the reservoir.
This reservoir is responsible for holding all the water that the plants need to make their food and grow. Sometimes there are also some nutrients, minerals, and trace elements in this water, which improves the overall quality of the plants.
Consequently, the bigger your reservoirs are, the more water you have, and the more stable your nutrient solution will be.
Since a lot of system failures happen due to unstable nutrient solution, with a stable one, you’re going to have a minimal amount of maintenance and monitoring.
As for the word “deep”, they’re called so because most of the roots of the cultured plants are submerged under the water for almost all of its time.
However, other hydroponic methods, such as the ebb and flow systems, tend to expose some of the root mass to the atmospheric air and drench the other part in water and alternate them throughout the day.
What are the Main Ingredients of Deep Water Culture Solutions?
These systems rely on a solution composed of three main ingredients. Here’s a quick rundown of each one of these ingredients and their significance.
What Are the Different Types of Hydroponics?
The name hydroponics is made up of two words; hydro which means water and ponics which means labor. There are typically 6 different types of hydroponic systems. Nevertheless, most people use a combination of several systems in their indoor gardens.
One of the clearest differences between regular soil agriculture and hydroponic systems is that the roots are submerged under the water surface in hydroponics, especially deep water cultures.
Since water lacks adequate aeration needed by the plant to perform photosynthesis process (water doesn’t have gaps and holes for air as soils do), the water needs to be highly oxygenated to compensate for the lack of air.
The first method to dissolve more oxygen in water is through air pumps. These air pumps work by transferring the oxygen from the atmosphere into the air diffuser inside the solution reservoir.
The diffuser’s job is to move the water and protect it from being stagnant, this movement breaks down the air stream into tiny air bubbles, which are much easier for the roots to absorb and utilize.
Another way to increase the solution’s oxygenation level is by an air stone. Air stones are inexpensive and small devices that you can add to the water reservoir in order to increase the concentration of dissolved oxygen in the water or nutrient solutions.
Air stones are available in various sizes to fit all water tanks of all sizes. They work by providing the tank with a huge number of tiny oxygen bubbles inside the tank with the help of the air pump that sits outside the water tank, where they're attached to each other by a small tube.
While an air pump can still get the job done without the need to add an air stone to the system, adding an air stone to the end of the tube helps in getting better diffusion results, and therefore, more dissolved oxygen in the solution than when using air pumps alone.
This method is the least popular aeration method for in-home water culture systems. In this technique, falling water splashes produce surface agitation needed for aeration of the nutrient solution.
You can control the amount of dissolved oxygen in this method by causing deeper agitation. This can be achieved by using a larger volume of water or splashing the water from a higher position.
The strong downward force it makes while hitting the water’s surface causes the deeper agitation.
Despite being unpopular on the home-grown farm’s scale, the falling water method is widely used in industrial-scale water culture systems. The reason behind preferring it by mass growers is the abundance of larger amounts of water they have compared to home growers.
As discussed in traditional soil growing, too much water can suffocate the plants. However, the suffocation of plants happens because over-watering means that there is no oxygen in the soil.
In the case of deep water culture and hydroponics, as we mentioned earlier, the water is rich with dissolved oxygen. If plant root is supplied with continuous water flow (provided that it has enough oxygen, nutrients, and lights), they’ll survive and thrive.
This means that you won’t have to continuously water your plants, which is one of the greatest benefits of hydroponics in general.
It’s necessary to keep the water temperature below 60°F to maintain optimum oxygenation and prevent the formation of fruits.
Soil is naturally rich with all kinds of nutrients. By removing the soil from the equation, we’re left with the only option of supplying the plants with all the nutrition they need artificially.
Nutrients and fertilizing materials used in deep water culture systems are available in both dry and liquid forms. They’re also both semi-synthetic or organic.
All these types are soluble in water and can be dissolved with specific quantities to produce the nutrient concoction needed in all kinds of hydroponic systems, including deep water culture.
A perfect nutrient mixture should contain all types of nutrients found in excellent natural soils. For example, it should contain micronutrients, such as trace quantities of iron, zinc, manganese, chlorine, boron, copper, and molybdenum.
Additionally, it should contain essential macronutrients, such as amino acids and nitrogenous bases, phosphorus, calcium, potassium, and magnesium.
Many of these nutrients are available in the form of fertilizers set and are sold commercially. By adding them to your reservoir according to the package directions, you should expect great results in less time.
However, you should only use fertilizing sets that are dedicated for hydroponics systems and not standard garden nutrients, as they contain different concentrations and components that aren’t always suitable for delicate systems such as deep water culture.
Moreover, fertilizers are usually designed for specific types of products. For example, some nutrient mixtures are best for greenery and growth of leafy vegetables, while others are designed for flowering plants. So it’s always important to choose the nutrient mix carefully.
The nutrient solution should be replaced every three weeks to remove any toxic waste produced by the plants.
What Are The Benefits of Deep Water Culture?
In addition to their advantages against traditional soil cultivation, deep water culture has some great benefits compared to other forms of hydroponics. Here’s a quick rundown of the benefits of growing in this system.
Deep water culture systems offer a lot of reasons to be one of the most popular hydroponic cultures. It’s so simple that many growers regard it as the easiest system to start with.
The only system that's considered simpler is the wicking system, in which you hang down the wick into the nutrient solution through a hole in the reservoir lid.
Doesn’t take Up Much Space
Another significant problem when it comes to traditional ways of soil agriculture is the need for a huge amount of space. This space is needed to grow food on a large scale to satisfy the modern-day capitalist world demands.
This challenges producers and large scale plant farmers to have a large stretch of land to grow enough food. Consequently, farms also have to be built tens of miles away from towns.
In a deep water culture, you can plant more in less land space, which saves space and transportation costs as well.
With deep water culture, all the optimum conditions for growth are met and continuously monitored. This allows the plants to grow quickly and efficiently.
For example, a lot of research papers confirmed that growing plants in deep water culture and hydroponic methods are much faster than traditional soil cultivation.
Challenges You Might Face with Deep Water Culture
Despite all its merits, deep water cultures have some challenging problems. These problems may arise due to several reasons. However, most of these issues can be avoided if you pay close attention and monitor your system regularly.
Require Adequate Adjustment
Deep water culture challenges appear more evident in a small system than a large-scale one. For example, while adjusting the system, it’s very easy to overshoot or under-calibrate the solution’s conditions.
Similarly, water temperatures need constant readjustments so you can maintain them at optimum levels.
Fluctuate Easily in Small Systems
Even if you adjust them correctly, water level, pH level, and nutrient concentration are always fluctuating in a small system due to limitations in space. This makes every variation in their number affect the whole system greatly.
Electricity Is Crucial
Since the pump is responsible for supplying the system with oxygen, any pump malfunctions or electricity outage can be highly dangerous to the survival of the system.
Without sufficient oxygen supply, the plants can easily drown in the low oxygen nutrient solution.
Ideal Plants for Deep Water Culture
The most suitable plants for this system are those who don't have to flower. The most notable examples are lettuce, herbs, tomatoes, and peppers.
Components Needed to Start a Deep Water Culture System
While there are different variations of deep water culture systems, they share some common components to get it started. You can buy a complete deep water culture set, or buy its components separately.
All you need to start a deep water culture system are some available materials. The required elements are a 5-gallon bucket, an air stone, an air pump, a net cup, and growing media of choice.
You’ll also need some instruments to run, connect, and monitor the system. These are items such as hydroponic nutrients, airline tubing, pH control kit, pH meter, and PPM meter. Let’s have a deeper look at these components.
The pH Control Kits
The pH is one of the most essential variables that you should control in hydroponic cultures. It’s like having a key to multiple locked cupboards. Each one of these cupboards is a nutrient element that is crucial for plants’ growth.
The pH plays an integral role in controlling the availability of ions and their best absorption by the plants. Controlling the pH gives the plant the optimum conditions to take the maximum benefits of your nutrients.
That’s why it’s important to have a good pH control kit. These kits allow you to go up and down on pH safely. Additionally, you need a digital pH meter to test the quality of your water quickly and efficiently.
T5 Grow Lights
If you’re looking for a way to give your growing plants a turbo boost, then you should also consider having T5 Grow lights. They’re a special type of light bulbs that became a standard for growing greenery indoors.
You can still use T12 or T8 bulbs as well. But if you’re on a hunt for the best, T5 is your way to go. They’re energy-efficient, long-lasting, and doesn’t put out much heat, so you won’t have to worry about raising the system temperature.
How to Build a Traditional Deep Water Culture System?
As the name suggests, traditional deep water culture is the oldest and simplest way to build the system. Now that you know the main components needed to start your first deep water culture system, let’s head to the steps of creating one.
Prepare the System
First, connect the air stone with the air pump through the airline tubing. Then place the air stone in the center bottom of the bucket.
The air stone can be placed anywhere in the bucket, but putting it in the center allows for even exposure to bubbles produced by the stone. After connecting everything, you should fill up the bucket with water.
Add Nutrients to the Water
After preparing the system, it’s time to give the plant some food so they can grow up healthy. Add the nutrient solution of your choice to the water to form the nutrient mix.
Both dry and liquid forms of nutrients can be used to form a nutrient concoction.
Adjust the pH level of the Solution
As we previously stated, it’s highly essential to keep the plants in a favorable pH level. To achieve this, simply start your pH meter and dip it into the solution as directed by the manual.
Make sure to give it a gentle shake to push the air bubbles away for the most accurate results. The ideal pH for deep water culture is around 5.8. Make sure to stay within a range between 5.5 and 6.5 to avoid wilting.
If you find your pH straying out of this range, just use the pH control kit to bring it back to normal levels. The kit has two bottles labeled “pH up“ and “pH down”.
If your pH is higher than 6.5, gradually add some of the “pH down” solution in the mix until you get back to the ideal pH of 5.8. If it’s lower than 5.5, use the “pH up” in the same manner. In both cases, you should keep regular monitoring of the pH of your solution.
Prepare the Plant
The plant should be placed in a net pot above the nutrient mix in the reservoir bucket. A net pot is a regular cup that looks like a mesh, allowing water to pass through it. This helps the plants to grow a strong root system spread in every direction.
You can use a regular pot with a hole in its bottom. However, this will allow the roots to grow in one direction only, which limits the strength of the root system. Most net cups in the market are made of rigid and reusable plastic, so they’re also safe to use in the system.
Start the Seeds
With everything in place, you can now start seeding your plant. Once the plant starts to germinate and form a root system that reaches the nutrient solution, the plant will grow exponentially fast.
The reason behind its fast growth is because the plant uses all of its energy to grow the plant, instead of wasting it in growing roots to search for water in the soil. With the availability of water and nutrients, the plant dedicated all of its energy to grow bigger.
As long as you keep the reservoir filled with oxygenated water and nutrients, the plant’s roots can stay submerged deep under the water surface for its entire life.
What Are the Other Types of Deep Water Culture?
Growing a deep water culture is a relatively simple procedure once you follow the instructions correctly. Yet, there are some variations in terms of scale and conditions that gave rise to multiple types of deep water culture.
Let’s have a look at each one of them, and see what they have to offer.
Recirculating Deep Water Culture
One of the most critical downsides of traditional deep water culture is that you can't expand your garden. The only way to scale it up is by getting new buckets (new reservoirs).
If you're looking for a way to scale your traditional deep water culture up, then the recirculating system is your way to go.
The main idea behind recirculating deep water cultures is how they're arranged. Instead of having 100 different systems with 100 reservoirs, you only get 100 buckets fed by one giant reservoir.
This way, it’s much easier to control the temperature, pH, and content of the nutrient solution. With all the buckets are connected to a central reservoir, all you need to do for a scale-up is to connect more buckets, add more water to the main reservoir, and re-calibrate its conditions.
So, what’s the “recirculating” part of the term?
If you remember the composition of your system, you’ll know the aeration is the key for this system to work. Just as it would be impractical to have separate reservoirs, the same goes for having a separate air stone for each bucket.
That’s where “recirculating” comes into play. When the nutrient solution moves from bucket to bucket, they have a flooding or a drain motion. This motion is enough to agitate the water like spray nozzles, which dissolves more oxygen in the water.
While this system is great, its main downside is that you have to be extremely careful with adjusting the central reservoir. Any major disturbance in the main feed reservoir can cause the whole system to fail.
Bubbleponic system is so closely related to deep water culture systems that some might regard it as nothing more than a clever adjustment to the main idea.
It works with the same traditional set-up and instrument. The only difference is that you add the water pump in the reservoir so that it shifts the nutrient mix to the top of the net pots.
That makes the bubbleponic system a top feeding system, which is highly advantageous in the early stages when the roots are short and are yet to reach the solution on their own.
This makes bubbleponics a great choice if you want to supercharge the germination phase of your deep water culture start. Bubbleponics' only downside is that it loses the advantage once the roots are long enough to reach the solution themselves.
There you have it. A comprehensive guide to starting your first deep water culture system.
If you’re a beginner in the deep water culture field, then you should know that this guide has everything you need to kick start your system.