Hydroponic Questions: Answers You Need for Hydroponics

In the dynamic realm of modern agriculture, hydroponics stands out as a game-changing technique. This soilless cultivation approach sparks a multitude of questions, from its basics to its benefits and techniques.

This list of frequently asked questions is your roadmap, navigating through the intriguing world of hydroponics.

Whether you’re a seasoned grower or a curious novice, join us to uncover the essentials of hydroponics – an innovation set to redefine farming for a more sustainable future.

What does hydroponic mean?

Hydroponic describes a method of growing plants without soil, in which nutrients and minerals are supplied to the root system via a nutrient solution.

By first clarifying what plants need, we can understand what hydroponics is and how it works.

Plants grow through the process of photosynthesis. Plants use sunlight and chlorophyll (a chemical inside their leaves), to convert carbon dioxide and water into glucose and oxygen. 

Soil is by no means a necessary ingredient in this recipe. 

Hydroponic means that soil’s jobs in the growing process are replaced with simple alternatives that give greater control to the grower.

What can be grown in hydroponics?

Virtually any plant can be grown in a hydroponic system. However, many plants only grow well in specific hydroponic systems, and some plants just don’t grow particularly well in any.

Leafy greens and most herbs are perfect for almost any hydroponic system. 

Vining crops like tomatoes, cucumbers, and peppers grow well with hydroponics but will take up more space and may require trellising. Melons are in the same boat—they do just fine without soil but are large and need some support.

Most root vegetables aren’t ideal for hydroponics, except for green onions and garlic. It’s not that you can’t grow a potato in a hydroponic system, it’s just inefficient and will lead to lackluster yields and wasted resources.

How does hydroponics work?

In hydroponics, plants get sunlight from the sun or grow lights, carbon dioxide from the air, and water from the nutrient solution you provide them.

In nature, the soil is needed to provide nutrients and to support the plant.

In hydroponics, growers eliminate the nutritional need for soil by mixing nutrient-rich liquids or powders with water to create a nutrient solution. 

And the structure and support usually provided by soil are replaced by a simple piece of plastic called a net cup, or with soilless growing media like rock wool, perlite, or coco coir.

Let’s look at a simple hydroponic system to see how this all comes together.

In deep water culture, a seedling is suspended above a reservoir of nutrient solution so its roots are submerged in the liquid and its stem and leaves are in the air. 

The roots absorb water and nutrients while the leaves take in carbon dioxide and light. This way, the plant gets everything it needs without soil—that’s the magic of hydroponics.

What are the main requirements of a hydroponic system?

For home hydroponic systems, several key requirements need to be considered to ensure successful plant growth. These requirements include:

1. Lighting: Adequate light is essential for photosynthesis. Home growers often use artificial lighting, such as LED or fluorescent lights, to provide the necessary spectrum and intensity for plant growth.
2. Growing medium: While hydroponics is soilless, a growing medium is still needed to support plant roots and retain moisture. Common options include coco coir, perlite, vermiculite, and rockwool.
3. Nutrient solution: Plants in hydroponic systems rely on nutrient-rich water to thrive. A balanced mixture of essential nutrients needs to be dissolved in the water and regularly supplied to the plants.
4. Water and oxygen: Hydroponic systems require a consistent supply of oxygenated water. Proper water circulation and aeration are critical to preventing root rot and providing oxygen to the roots.
5. pH and EC control: Monitoring and adjusting the pH (acidity or alkalinity) of the nutrient solution as well as the electrical conductivity (EC), which measures nutrient concentration, is essential for optimal nutrient uptake.
6. Temperature and humidity control: Maintaining appropriate temperature and humidity levels is crucial for plant growth. These factors can vary depending on the plants being grown, but generally, a stable environment promotes healthy growth.
7. Space and support structures: Adequate space is needed for the hydroponic setup, including reservoirs, trays, and support structures. Consider the size of the plants at maturity, and plan accordingly.
8. Pest and disease management: While hydroponic systems can reduce the risk of certain soil-borne pests and diseases, it’s still important to monitor for any issues and take appropriate measures to prevent and address them.
9. Monitoring and automation: Many modern home hydroponic systems offer monitoring and automation options. These tools help maintain optimal conditions by adjusting lighting, nutrient delivery, and other factors based on preset parameters.
10. Knowledge and education: Successful home hydroponics requires a solid understanding of the chosen system’s operation, plant biology, and best practices. Educating yourself through resources and guides is crucial to achieving the best results.

What are the 6 types of hydroponics?

Here are the six types of growing systems used in hydroponics:

1. Wick system – A simple, passive system in which nutrient solution is supplied to the root system via a wick that draws the liquid up from the reservoir to the growing media through capillary action. 
2. Water culture – Another very simple method, water culture involves floating or suspending plants atop a reservoir so that their roots hang directly into the nutrient solution. 
3. Ebb & flow – In ebb & flow hydroponics, plants are positioned in growing channels. Using a timer and water pump, the channel is periodically flooded with a nutrient solution that contacts the root system, supplying water and nutrients. During the off-time, root systems hang in the air, giving adequate aeration and eliminating the need for an air stone.
4. Drip systems – One of the most common hydroponic methods, drip systems use irrigation hoses to constantly or periodically drip nutrient solution onto a plant’s growing media. The nutrient solution is then either recycled back into the reservoir or discarded. 
5. N.F.T. – NFT, or, nutrient film technique, uses a growing channel to supply a thin film of nutrient solution to a plant’s root systems. The roots hang in the channel that is mostly filled with air, apart from the low and steady flow of solution. This way, roots simultaneously get the oxygen, water, and nutrients they need.
6. Aeroponic – In perhaps the most advanced form of hydroponics, aeroponics uses a water pump, timers, and sprayers to supply root systems with frequent mists of nutrient solution. No growing media is used; instead, the roots hang bare in the air, giving rise to this method’s name.

Which hydroponic system/method is best?

There is no “one size fits all” solution in hydroponics. No one system is better than another, but each has its pros and cons.

What system is best for you depends on what you’re growing, how much space you have, your budget, your level of expertise, and how much time you are willing to devote to the system.

For example, a commercial grower that wants to fill their greenhouse with hydroponic tomato plants will likely have the most success with Dutch Buckets, a type of drip hydroponics system.

Why would this system fit this grower?

1. The grower has a large space to fill. 
2. Tomatoes are a heavy-feeding plant.
3. Tomatoes yield better when supported and trellised. 
4. The grower probably wants a customizable system that gives him or her plenty of control.

Dutch Buckets deliver on all of these needs.

1. Dutch Buckets are highly scalable.
2. They deliver lots of water and nutrition via constant or timed drip irrigation.
3. The bucket is filled with growing media like perlite, which gives plants great support. Trellises can be built directly into the buckets, or the plant’s vines can be hung from the roof of the greenhouse.
4. Finally, Dutch Bucket systems can be tweaked with timers, heaters or coolers, pumps of different flow rates, buckets with different growing media, etc. This gives the commercial grower full control.

On the other hand, if a casual gardener wants to grow one or two basil plants to use for home cooking, a simple Kratky system would work best.

This water culture system is incredibly simple, passive, and doesn’t require any special equipment or knowledge. Also, the Kratky Method is perfect for growing leafy greens and herbs.

What are the advantages of hydroponics?

The main advantages of hydroponics are greater water efficiency, less nutrient runoff, the quantity and speed of yields, fewer pests and diseases, no arable land is needed, and it takes up less space than traditional farming.

Water efficiency – Growing hydroponically uses significantly less water than traditional, soil-based growing, especially in systems that reuse nutrient solutions. According to the U.S. National Park Service, hydroponic systems use as much as 10 times less water than field crop watering methods.

Less nutrient runoff – In hydroponic systems, water and fertilizer can be recollected after use. From there, growers can properly dispose of them in a way that doesn’t harm the environment. Most farms that grow in soil can’t do anything about nutrient runoff, namely nitrogen runoff, in which nitrogen from fertilizer contaminates groundwater and bodies of water, disrupting aquatic ecosystems.

Size and speed of yield – Numerous tests have shown that hydroponics can produce better yields and do so faster than other methods. This is because hydroponics allows for greater control of nutrient levels, temperature, and light and exposes plants to fewer pests and diseases.

Fewer pests and diseases – Because hydroponic systems aren’t exposed to soil that houses many insects, fungi, and microorganisms, they are less susceptible to pests and diseases. Also, keeping plants in individual containers or small groups of containers lowers the chances that a sick plant will infect another one.

No arable land required – Because soil is replaced with soilless growing media and nutrient solution, land access isn’t as much of an issue. People in cities or other areas without large plots of high-quality soil can still grow large quantities of fresh fruits and vegetables using hydroponics.

What are the disadvantages of hydroponics?

The disadvantages of hydroponics include the upfront cost, technology reliance, and susceptibility to waterborne diseases.

Upfront costs – Building some of the more complex hydroponic systems can be expensive. Some growers aren’t able to make the initial investment required to begin operation.

Reliance on technology – Certain hydroponic systems are extremely reliant on technology to the point that a power outage could cause a significant loss of crops. For example, an NFT system uses a water pump to feed plants. If the pump were to lose power, the channel would run dry. If you couldn’t water the plants before the power returned, your plants could be hurt or outright ruined.

Spread of waterborne diseases – With recirculating hydroponic methods, waterborne diseases can be an issue. If just one plant becomes infected with a pathogen that can be carried through water, the entire system could become compromised. 

What is the main disadvantage of hydroponics?

One of the main disadvantages of hydroponics is its initial setup cost. The infrastructure required for hydroponic systems, including pumps, grow lights, nutrient solutions, and climate control, can be expensive to install and maintain.

While the long-term benefits in terms of higher yields and resource efficiency can offset these costs, the upfront investment can be a barrier for some individuals or small-scale operations.

Do hydroponic vegetables taste different?

There is some debate about the flavor of hydroponic vegetables. The quick answer is yes, hydroponic veggies do taste different than ones grown in soil.

To elaborate, the flavors of all plants change depending on many factors, like the type and quality of soil or the time of year. 

A tomato grown in my garden will taste slightly different than one grown in yours. 

The great thing about hydroponics is the control you have over the conditions your plants grow in. Nutrient levels, hydration, and temperature can all be controlled to give you the desired taste.

In short, plants grown under different conditions may taste different, but hydroponic plants taste just as good as ones grown in soil—there is no evidence to the contrary.

Are plants grown hydroponically organic?

In general, hydroponic systems can present challenges when it comes to meeting traditional organic farming criteria.

Organic farming emphasizes the use of natural and sustainable practices, including soil health and the avoidance of synthetic fertilizers, pesticides, and other chemicals.

Hydroponic systems, which involve growing plants without soil in nutrient-rich solutions, may use synthetic nutrients to feed the plants. This use of synthetic inputs can be a point of contention when it comes to organic certification.

How do you keep your hydroponic system clean?

To maintain a clean and functional hydroponic system while avoiding potential damage, it’s essential to prioritize proper cleaning practices.

The best option for cleaning is to rinse thoroughly to wash and eliminate any residue or buildup that might accumulate.

This step ensures that no remnants left behind by cleaning products remain, which could potentially harm your plants or disrupt the system’s balance.

While some cleaning products might seem appealing, it’s crucial to refrain from using bleach in hydroponic systems. Bleach is not recommended due to its potential to cause harm to plants and disrupt the delicate nutrient balance.

Instead, focus on a gentle yet thorough approach by regularly rinsing and washing the components of your hydroponic system. This strategy helps maintain optimal conditions for your plants’ growth while minimizing the risk of any adverse effects from cleaning agents.

Can you make your own hydroponic nutrient solution?

You can make your own hydroponic fertilizers at home, saving you money and giving you greater control over the balance and amount of nutrients.

While many growers enjoy the convenience of a pre-mixed liquid container of fertilizer, others buy dry ingredients in bulk and mix them with water themselves. 

Here is a simple recipe for a DIY general-purpose hydroponic fertilizer. This recipe is a fertilizer concentrate, meaning one gallon of concentrate is enough to create 250 gallons of nutrient solution.

Step 1: Pour one gallon of distilled or reverse osmosis water into a clean bucket.

Step 2: Add 600 grams of Masterblend 4-18-38 Tomato & Vegetable Formula. Mix well. 

Step 3: Add 300 grams of Epsom salt. Mix well. 

(Optional) Step 4: Add 1.5 grams of sodium benzoate, a preservative, to help your fertilizer last longer. Mix well.

That’s all it takes! This general-purpose fertilizer will be significantly cheaper than buying pre-mixed bottles from the store.

And here is a super easy recipe for a calcium nitrate fertilizer concentrate.

Step 1: Pour one gallon of distilled or reverse osmosis water into a clean bucket.

Step 2: Add 1,100 grams of calcium nitrate. Mix well. 

This fertilizer is for amending your nutrient solution or growing medium with nitrogen and calcium which helps with cell formation and neutralizes acids that are toxic to plants, among other things.

You can buy all of the ingredients needed for this recipe in this kit.

Credit to ChilLED Grow Lights for these fertilizer concentrate recipes!

Can I use soil nutrients for hydroponics?

Using soil nutrients for hydroponics is generally not recommended. Soil and hydroponic systems have different nutrient requirements due to the distinct ways in which nutrients are delivered to plants. While both systems provide plants with essential nutrients, they do so in different ways.

Soil nutrients are designed to work within the context of soil biology, which can include interactions with microbes, organic matter decomposition, and pH buffering.

In a hydroponic system, these interactions are absent, and the nutrient solution needs to be carefully balanced and controlled to avoid issues like nutrient imbalances, pH fluctuations, and salt buildup.

Using soil nutrients in a hydroponic system could potentially lead to imbalances, poor plant growth, and even damage to the system.

It’s best to use nutrients specifically designed for hydroponics to achieve the best results and maintain the health and productivity of your plants.

Is sunlight required for hydroponics?

Light is required for hydroponics, but not necessarily sunlight. 

You can grow hydroponically outdoors or in a greenhouse where your plants will get all of the light they need naturally. Or, if you have indoor space with sufficient natural lighting, that will also work.

Many hydroponic growers grow exclusively indoors, replacing the sun with grow lights. 

Grow lights use either LED, fluorescent, incandescent, or HID bulbs. 

Using grow lights instead of relying on the sun gives growers greater control and allows them to grow year-round, even during winter when sunlight is sparse.

Are LED lights good for indoor hydroponic gardens?

LED lights are the go-to choice for many hydroponic growers. They work well with almost any setup and offer some unique advantages when compared to other types of grow lights.

LEDs are the most energy-efficient type of grow light and have a longer lifespan than other bulbs, typically around 50,000 hours. This can save you money, especially if you plan on using many of them.

Also, LED grow lights are usually smaller and more compact than their counterparts, giving you more real estate in your grow room,

Lastly, LEDs run significantly cooler than other lights, reducing the risk of heat burn on your plants.

How long should I keep my grow lights on every day?

The duration of time you should keep your grow lights on in a home hydroponic system depends on the specific plants you are growing, their growth stage, and the type of lighting you are using.

Here are some general guidelines to help you determine the appropriate light duration:

1. Seedlings and Young Plants: Seedlings and young plants typically require more light to encourage healthy growth. During the early stages, you may need to provide around 14 to 18 hours of light per day. This extended light exposure helps promote strong root development and prevent leggy growth.
2. Vegetative Growth: For plants in the vegetative growth stage, which includes leafy growth and the development of stems, you can provide around 12 to 16 hours of light per day. This range of light exposure is generally suitable for many plants during this stage.
3. Flowering and Fruiting: When plants transition to the flowering or fruiting stage, they often require a change in light duration to mimic natural daylight changes. In this stage, it’s common to provide around 10 to 12 hours of light per day. This reduced light exposure signals to the plants that it’s time to focus on producing flowers and fruits.
4. Light Type: The type of grow lights you’re using can also influence the duration. LED grow lights are more energy-efficient and emit less heat, allowing you to keep them on for longer periods. Traditional high-intensity discharge (HID) lights may generate more heat, so you may need to consider temperature management.
5. Monitoring Plant Response: Pay attention to how your plants respond to the light duration. If they are growing vigorously, healthy, and not showing signs of stress, you’re likely on the right track. However, if you notice signs of overexposure (such as leaf burn) or underexposure (leggy growth or lack of flowering), you may need to adjust the light duration accordingly.
6. Consider Light Intensity: Along with duration, the intensity of light is crucial. Different plants have varying light intensity requirements. Make sure the light is positioned at an appropriate distance from the plants to ensure they receive the right amount of light without causing stress or damage.

Does hydroponics use a lot of electricity?

Electricity consumption in hydroponic systems varies based on factors such as system type, lighting, size, and efficiency.

• Artificial lighting, used to provide the necessary spectrum for plant growth, is a major contributor to electricity usage. The type, wattage, and duration of lighting significantly impact consumption.
• The hydroponic system’s design also influences energy needs, with systems requiring recirculating pumps for nutrient delivery consuming more than those with less water movement.
• Climate control is crucial in hydroponics, potentially involving heaters, fans, and ventilation systems that consume electricity.
• Efficiency and automation play a role in optimizing energy usage. Utilizing energy-efficient LED lights, employing timers for lighting regulation, and implementing smart controllers can curtail electricity consumption.
• The scale of your operation matters as well; larger setups demand more lighting, pumps, and climate control equipment.

While hydroponic systems can be energy-intensive, they often yield more while using resources more efficiently than traditional farming. The potential for higher productivity may offset energy costs, especially with efficient practices.

How do I prevent root rot in my hydroponic system?

Preventing root rot in your hydroponic system involves maintaining optimal conditions for plant roots while minimizing excess moisture that can lead to fungal growth. Here’s how to prevent root rot effectively:

1. Opt for plant varieties that are less susceptible to root rot. Some plants are more resilient in hydroponic environments.
2. Before setting up any type of hydroponic system, ensure that all equipment, including containers, growing medium, and tools, are properly cleaned and sterilized to minimize the introduction of pathogens.
3. Select a hydroponic growing media that provides good drainage and aeration. This helps prevent water from pooling around the roots.
4. Water quality is important. Don’t allow the roots to sit in stagnant water for extended periods.
5. Implement a watering schedule to provide intermittent hydration, allowing roots to access oxygen between waterings.
6. Regularly check the water levels in your hydroponic system to prevent flooding.
7. Introduce oxygen into the nutrient solution using air stones or diffusers. Oxygen-rich water helps inhibit the growth of anaerobic pathogens that cause root rot.
8. Root rot pathogens thrive in environments with imbalanced pH. Regularly monitor and adjust pH to keep it within the appropriate range for your plants.
9. Ensure that the nutrient solution’s EC remains within the recommended range to prevent excessive nutrient buildup that could encourage root rot.
10. Keep the root zone dark to discourage algae growth. Algae can create a conducive environment for root rot pathogens.
11. High humidity can promote fungal growth. Proper ventilation and dehumidification help prevent excess moisture.
12. Keep the root zone at a temperature range that is comfortable for the plant species you’re growing. Extremely cold or hot conditions can stress plants and weaken their defenses against pathogens.
13. Routinely check the condition of your plant roots. Healthy roots are white or creamy in color; brown or slimy roots are signs of potential root rot.
14. If you notice signs of root rot in a plant, isolate it immediately to prevent the spread of pathogens to healthy plants.

How do you get rid of pests in hydroponics?

Steps and methods to control pests in hydroponics include:

1. Start with healthy plants, quarantine new ones, and maintain cleanliness.
2. Identify the specific pest you’re dealing with to tailor your approach.
3. Combine methods like beneficial insects, cultural practices, and physical barriers.
4. Introduce predators like ladybugs or mites to manage pests naturally.
5. Keep a clean environment, remove infested plants, and practice good hygiene.
6. Use screens, nets, or manual removal to minimize pest presence.
7. As a last resort, opt for hydroponic-approved pesticides, following instructions carefully.
8. Check plants frequently for signs of pests to catch issues early.
9. Isolate infested plants to prevent spreading.
10. Maintain records to track patterns and refine your pest management strategy over time.

Is hydroponics healthier than soil growing?

Food grown in hydroponic systems can be just as healthy, if not healthier, than food grown in soil.

Neither method is inherently superior in terms of producing more nutrient-dense and healthy food.

What it all comes down to is the availability of nutrients, water, and light during growth. Because hydroponics allows for complete control over these factors, well-grown hydroponic fruits and vegetables can be some of the healthiest ones out there.

Is hydroponics cheaper than soil growing?

The affordability and return on investment of hydroponic growing methods vs. traditional growing methods are complicated and debatable.

That being said, hydroponics does take the edge in certain areas. 

Hydroponics uses significantly less water, as much as ten times less. 

The cost of land or space for hydroponics can be significantly cheaper. Land with arable soil is much more expensive than the potentially barren, rocky, snowy, or concrete-covered land that can be used for hydroponics.

Because plants aren’t grown in soil, labor costs related to weeding, tilling, and spraying plants with pesticides can be eliminated.

Not only is the land required for hydroponic growth cheaper, but in general hydroponic methods are more space-efficient. Methods like N.F.T., ebb & flow, and aeroponics are commonly configured vertically, taking more advantage of growing space.

Lastly, because hydroponic methods can yield more and do so faster, revenues can be higher.

Can you transfer plants from soil to hydroponics?

Yes, it is possible to transfer plants from soil to hydroponics, but the process requires careful consideration and proper adjustments to ensure a successful transition.

Here are the general steps to follow when transferring plants from soil to a hydroponic system:

1. Choose suitable plants: Not all plants are equally suited for hydroponic cultivation. Leafy greens, herbs, and some fruiting plants tend to adapt well to hydroponic systems.
2. Prepare the hydroponic system: Set up your hydroponic system, and make sure it’s properly calibrated and functioning before transferring the plants.
3. Select healthy plants: Choose plants that are healthy, free from pests or diseases, and have strong root systems.
4. Prepare plants for transfer: Gently remove the plants from their soil pots, shaking off excess soil. Gently rinse the roots to remove any remaining soil. Trim any damaged or excessively long roots.
5. Transition period: Plants that were previously grown in soil may experience some shock when moved to a hydroponic system. Give them time to adapt gradually by initially placing them in a separate hydroponic container with a growing medium (like perlite) to help the roots adjust to the new environment before placing them into the main hydroponic system.
6. Adjust nutrient solution: It’s important to monitor the nutrient levels. Adjust the nutrient solution to match the specific needs of the plants you’re transferring. Start with a diluted solution and gradually increase its strength as the plants acclimate.
7. Monitor conditions: Keep a close eye on the plants during the transition period. Watch for signs of stress, such as wilting or yellowing leaves, and adjust factors like lighting, nutrient concentration, and pH as needed.
8. Transplant to main hydroponic system: Once the plants have acclimated to the hydroponic environment, you can transplant them to the main hydroponic system. Secure them in place and ensure their roots are properly submerged in the nutrient solution.
9. Ongoing care: Regularly monitor and adjust nutrient levels, pH, and other environmental factors. As plants adapt to their new hydroponic home, you may notice changes in their growth patterns and nutrient requirements.

Keep in mind that the transition from soil to hydroponics can be a bit challenging for plants, and success may vary depending on the type of plant, the health of the plants, and your attention to details.

How does rain affect hydroponics?

If hydroponic containers are placed outside, rain can overfill reservoirs and dilute the nutrient solution. If left unchecked, this could cut off plants’ roots from oxygen and lead to malnutrition problems.

The simple solution is to cover your containers and reservoirs with plastic or house them under a roof, tent, or tarp. 

As long as your system isn’t being frequently bombarded with rain, it shouldn’t be a problem.

Can you do hydroponics indoors?

Plants can be grown hydroponically indoors. Many growers exclusively use indoor hydroponic garden systems because it allows them to have greater control over the growing environment.

The biggest concern with indoor growing is making sure your plants get adequate light. If you don’t have access to large windows or a roof that can let in sunlight, you will need to use grow lights. 

A great option is to use full-spectrum LED grow lights. These come in many shapes, sizes, and intensities. LED lights are more energy-efficient than most other grow lights and produce less heat.

Is hydroponic farming profitable?

Hydroponic crop farming is an $831 billion industry in the U.S. where there are over 3,000 hydroponic farm businesses, according to research by IBISWorld.

Thousands of growers make their livings off of hydroponic farming. There is no denying that it can be profitable!

Many factors come into play when we talk about profitability, and no two hydroponic operations are the same.

However, with the right knowledge, equipment, and business savvy, hydroponic farming can be successful and profitable at many scales, from a home grower’s side hustle to a multimillion-dollar international business.