Hydroponics Basics: 16 Beginner Questions Answered

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.

Do hydroponic vegetables taste different?

There is some debate around 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.

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.

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 rockwool, 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.

Can you make your own hydroponic nutrients?

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

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 hydroponics?

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.

What are the 6 types of hydroponics?

Here are the six types of hydroponic systems:

  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 of 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. – N.F.T., or, nutrient film technique, uses a growing channel to supply a thin film of nutrient solution to plant’s root systems. The roots hang in the channel which 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.

Dutch Bucket Hydroponic 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 its greater water efficiency, less nutrient runoff, the quantity and speed of yields, fewer pests and diseases, that no arable land is needed, and that 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 ten 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, light, and exposes plants to fewer pests and diseases.

Fewer pests and diseases – Because hydroponic systems aren’t exposed to soil which 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 N.F.T. 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. 

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 is 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.

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 grow indoors 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.