What are Hydroponic Systems?
Hydroponic systems deliver nutrient solution to plants in place of soil. Hydroponic systems continue to increase in popularity since they grow edible plants almost anywhere indoors or at home. They’re cheap, flexible, and scalable. Six basic types of hydroponics exist today and all of them deliver nutrient solution to plant’s roots in via one method or another.
The only downside to a hydroponic system is its power usage compared to harvest output. Traditional farming which uses the sun for power will always use less power than a hydroponic system. Hydroponics systems almost always require electricity for light sources if not water pumps. Traditional gardening requires no electricity. Additionally, hydroponics won’t work for every type of plant. Modifications must be made for tuber plants and pollinating plants to ensure their proper growth and harvest.
What are the Best Types of Hydroponic Systems?
There are many different types of hydroponic systems. These systems differ in how they distribute nutrient solution to the plants. Since plants like adequate nutrients and oxygen, it’s important that each system spreads nutrient solution equally. Each of the systems has pros and cons so it will depend on the goals, plant size, and scope you intend for your hydroponic systems. While most plants work well in any system, some specific plants will struggle in systems that cannot accommodate their preferred size or root structure.
Excellent growth results can be achieved in any hydroponic system with any nutrient solution. More important than which types of systems you choose is the attention to pay to it. If you don’t check the pH and EC in your system often enough, you can kill the plants regardless of how great the plants would otherwise grow.
Here are six basic hydroponic systems:
Ebb and Flow Flood
An ebb and flow hydroponics system simulates a regular watering cycle like a sprinkler system in a yard. Due to a timer, a water pump cycles nutrient solution into the basin holding the crops. After the ebb flow completes its cycle the system drains the excess nutrient solution back into the reservoir. This flood and drain system washes the roots of the plants beneath the growing media regularly but also keeps them from rotting or drying out. It’s the right mix of wet that root systems grow best in.
A strict schedule is required for ebb and flow systems which is almost always automated. These systems work well for more experienced gardeners since they require knowing correct flood and drain timings for each type of plant. Ebb and flow systems also work well with any number of growing medium.
Deep Water Culture
Deep Water Culture or DWC are types of water culture systems that resemble an aquarium in many ways. The nutrient solution located beneath the plants constantly bubbles as an air stone set at the bottom of the reservoir adds constant oxygen to the water. This system works well by distribution water and nutrients constantly but requires an air pump. This oxygen prevents roots from drowning since the roots of the plants will be entirely submerged in nutrient solution and drown without it.
Deep Water Culture hydroponics is beginner-friendly and simple in terms of material and construction. A Deep Water Culture can be set up in minutes and monitored a few minutes a day to produce results. It’s also very water-efficient since some versions require no added nutrient solution for the life cycle of the plant.
Aeroponic systems differ from other types of hydroponic systems in that the water is delivered via a mist rather than flushing the roots with water. The mist system keeps the roots of the plants happy without the possibility of drowning the roots or giving them root rot from too much water exposure. Because the nutrient solution is delivered without submersion, plant roots never drown.
Aeroponic systems are one of the most expensive types of hydroponic systems since it requires installing many high-pressure nozzles into the water culture system. Additionally, any failure or clog in the nozzle can spell doom for plants.
A wick system is a hydroponic system before hydroponics got its fancy name. It takes less maintenance than any other type of system. This simple growing technique was used in the ancient world. It uses a rope or other water-bearing material to move water up from a container to the roots of thirsty plants. No pump is required. A wick system is entirely passive. Note that wick systems don’t work for larger plants since they need more nutrient solution than wicking will provide for them. Wick systems are great for beginners or those interested in a hydroponic system with little upkeep. Since the plant draws the nutrient solution by ‘sipping’ on water drawn up by the rope, there’s little risk of root rot.
Nutrient Film Technique (NFT)
This type of hydroponic system is commonly found in commercial growing applications. This type of hydroponic system can be easily expanded to include hundreds or even thousands of plants. The main feature of nutrient film technique is that plants are placed in rows where the roots are suspended above a narrow channel flowing beneath them. On the end of the row is elevated so that gravity naturally moves the water down past the roots of the plants before being collected at the end and recycled back through the system. Nutrient Film Technique makes building vertical and multiple rows of plants easy so that they can be observed and harvested continually. It’s great for gardeners interested in increasing their production over time as they add new rows and enlarge their systems.
Recently, commercial hydroponic gardeners have moved away from this type of hydroponic system for several reasons. On large scales, there is a risk of spreading diseases since all the crops are exposed to the same nutrient solution. Some fruiting plants have been found to benefit from periods of being removed from a nutrient solution, making them far more suitable from a flood and drain or ebb and flow system to help them reach their maximum.
A drip system is a type of hydroponic system that involves running a tube to each individual plant where the nutrient solution is pumped drip by drip into each cup where the crop sits in its growing medium. It’s less common to find this set up in homes or smaller operations because there is less advantage to adding a tube to each individual plant. Once the excess water reaches the reservoir below, the water returns as a recovery drip to again get correct ph and nutrient balanced solution delivered back up top.
These systems are, however, relatively cheap when up and running, and in larger operations each plant can be monitored and removed as needed, making it a cost-effective type of hydroponic system. Drip systems, like many of the other systems, rely on a pump to deliver nutrient solution can be sensitive to power outages or pump failure. The conditions of crops rapidly deteriorate if for any reason they are not constantly fed from the small hose dripping into their pots. A drip system can be a great way to grow different crops in the same space since each one receives individual attention.
Rotary hydroponic systems are a recent development and testing of their benefits is ongoing. Their unique configuration contains a wheel of leafy crops that circle and face inward toward a central 360 degrees light. Most systems rotate the wheel of plants once an hour. This setup causes the plants to respond to gravitational pull which can bring taller, faster plant growth.
As the name suggests, this system uses a fogger to deliver nutrient-rich water. These systems are very similar to aeroponics with the same benefits. The downside to such systems is that the atomizer delivering the fog can heat the air if left long enough and nutrient fog can build up salts, clogging the fogger. Like all hydroponic systems, these systems need regular observation to give growing crops the best chance.
What are some Types of Aggregates used in Hydroponic Systems?
The term ‘aggregate’ describes the growing medium or root support structure used in a hydroponic system. Usually, an inert (preferably pH neutral material) is used as a filler to give root structures enough support in the absence of soil. Aggregates come in different types to accomplish this task.
Cheap forms (often free) of growing medium include sawdust, gravel, sand, and vermiculite. Granular aggregates such as these are generally inexpensive, but all of them present the risk of clogging recirculation systems. Additionally, certain materials like gravel will affect the pH balance of your water.
The next type of plant medium are clay pellets. These pellets are created from baked clay and resemble large pebbles. One of the great benefits of these types of mediums is that they are reusable. The pellets contain tiny holes that allow water and oxygen to reach the plants without suffocating them and work well in almost any system.
Natural substances such as coconut husks and rice hulls are another option. Since these substances are taken directly from other plants they work well. The only downside to them is that they can decay over time and will need replacing.
Rock substances like rockwool, perlite, and pumice make up the last general grouping of growing mediums. These substances are all composed of various rocks or minerals. Since in most cases they’re ground down into a dust or powder, they allow water and air to move freely to the plant’s roots. However, the dust from these materials can be harmful to humans when inhaled so use them with caution.
A DWC hydroponic system doesn’t require a growing medium at all. The roots simply sit in oxygenated water. Since the nutrient-rich water receives added oxygen, the roots don’t drown. It’s still possible for roots submerged in water to experience root rot so you will need to observe them carefully.
What do I Need for a Hydroponic System?
Hydroponic systems, regardless of which of the different types of system you use, need the following:
- a light source
- nutrient solution
- a hydroponic system
- a growing medium
Crops grow best when a full spectrum light source is used. Plants need different amounts of light at different stages of their growth cycle. Experienced growers move their crops between different light sources during their life cycle to ensure their growing plants reach the maximum potential. For beginners, daylight can provide enough light to your system, but advanced students will want to buy or build their own light systems to keep their leafy greens happy.
LED lights can be a useful way to ensure your system receives enough light without worry of expense or heat. LED lights emit little heat which is excellent since the heat from a light source can potentially damage crops after they spend hours on end exposed.
Always remember that pH and nutrient solution balance is key to proper growth and a healthy root system. Growing plants hydroponically will require regular care and attention as you learn what works best in your system. Vegetables grow differently from one another and which vegetable you have in the pot will need slightly different pH to thrive. Thankfully, most consumer nutrient solutions provide the right balance of nitrogen, phosphorous, and other nutrients that your crops will require.