You’ve probably heard of hydroponic plants, but you’re not sure how they get their nutrients. Well, we can’t tell you all the details in just one blog post, but here is a small primer on the subject.
A hydroponic plant’s roots are either submerged in an inert solution that contains dissolved nutrients (like nutrient film technique) or they make contact with a nutrient solution that is continuously pumped through a system of pipes (a nutrient drip). The solution is periodically replenished with fresh nutrients. The nutrient solution can contain water-soluble nutrients, a gelling agent, and an oxygen source.
In water culture the plant root system is suspended in the air and provided with a constant flow of fresh nutrients. In ebb and flow nutrient solutions are pumped into the growing media where they remain for a time before being drained away. Although there are many variations, most hydroponic systems use some combination of these two techniques.
One advantage to hydroponic gardening is that by dissolving oxygen directly into the nutrient solution, root systems are able to utilize more dissolved oxygen than they would if left exposed to air alone, which allows roots to grow more quickly because they are not limited by available oxygen.
Of course, there is a downside to this practice. Although hydroponic systems can benefit from the additional oxygen that dissolved oxygen provides, they are also more prone to chlorosis when compared to growing systems in which the nutrients are provided by an inert gas like nitrogen or carbon dioxide.
Depending on how well your plants have adapted their metabolisms to handle higher levels of dissolved oxygen, it may be possible for you to increase the amount of oxygen available to them without undermining their ability to use calcium and magnesium. However, if your plants do not react well to high levels of dissolved oxygen it may be best not test your limits with water culture.
What is needed for a hydroponic system?
A container – The size that you choose will depend on the size of your plants and how much space you have.
A Grow Media – This is the material that allows for good drainage. Rockwool, perlite, and vermiculite are great options.
Pond Liner (optional) – If your container has a top, then you may need this to keep your nutrients from draining into the ground.
A Nutrient Solution – In order for your plants to thrive, you will need to add compost tea or water-soluble fertilizer to your hydroponic system frequently.
The way you set up your system will depend on how you choose to provide the nutrients. A nutrient drip system will require a source of oxygen and pumps which can be installed either in a reservoir or directly into the growing media.
In order to prevent waste, it may be beneficial to make the nutrient drip pump directly into another reservoir before pumping it into your hydroponic system. The water from the nutrient drip system can then be pumped through an irrigation system, filtered, or otherwise processed if desired before going back into your hydroponic garden.
A reservoir system will require the use of a pump that can be installed in your reservoir. This type of system will have the advantage of making it easy to add extra nutrients without adding them to your nutrient solution, but it will be more difficult for you to remove excess nutrients or water from the system.
What are the disadvantages of hydroponics?
Watering – It is possible to over water your plants in a hydroponic system, whereas with a soil system you will not need to water as often. However, if you are unable to provide the necessary nutrients for your plants this can be an issue. It may also be more difficult to control watering if you are using a reservoir or drip system rather than the container method.
Feeding – With hydroponics it may be easier for certain pests, like aphids and attack mites, since they can feed on your leaves and stems without doing any harm. However, if you are using an inert gas or other methods of fertilization, you may not have this problem.
Nutrient Solution – Hydroponic systems require the use of a nutrient solution and pumps. If your system is not properly maintained it can be very damaging to your plants. Also, if you have ever had a leaky gutter or a kitchen sink with a slow drip, then you know how easy it is to have nutrient solution flow from your hydroponic system back into the reservoir. It only takes one small leak to ruin your plants.
Cultivation Space – Since hydroponic systems are usually indoors they require more space in order to operate efficiently.
Water Solution – Most hydroponic systems require the use of water as part of the nutrient solution. It is an efficient method to provide nutrients but it can also be a great source of contamination if the system does not remain sealed properly. Also, it must be understood that these solutions require a significant amount of energy to keep them running around the clock and this energy will add up over time.
Nutrient Solution Replenishment – Another concern with hydroponics is that it may become necessary to replenish your nutrient solution every few days since you will need to make sure you remove old nutrients when you add new ones. This can be a time consuming process and a great opportunity for contamination.
Water – The water used for hydroponics can be considered a serious contaminant. Depending on the profession you hold, the type of work you do, and the location where you live water may also be an important consideration.