Hydroponics 101

Well my friends, I am back again to give you a basic understanding of the fundamentals of hydroponics. This article is, in part, an adaptation of a course that I have given to a number of hydroponic store assistants over the years to enable them to better help their customers (you). By the time we finish this basic course (think of it as hydroponics 101) you will have an excellent grasp of the basic skills and theory that will help you to become a more consistent and successful grower.

As for the more experienced growers that have read this far, I can hear your groanings already!

“I don’t need to read this, I’m a great hydroponic gardener,” and

“I’ve been growing for years so how would this possibly help me?”

Well folks, as bizarre as this may sound, experienced growers can actually learn quite a bit and often you might be reminded of important things forgotten over the years. Remember, if you have a good grasp of the fundamentals of hydroponics, then you will by default, obtain far more consistent results and quite often increased yields from putting into practice what you learn here. Hey, isn’t this why you’re reading this magazine, so you can get a Maximum Yield?

So, What is Hydroponics?

Quite simply, hydroponics is the art or science of growing plants without the use of soil.

The word hydroponics comes from the Greek words “hydro” which means water and “ponos” meaning work or, taken literally, “water works” and man, does it ever! Done correctly, hydroponics performs better than any other form of gardening. Don’t let hydroponics scare you though, as hydroponics is only a technique used to grow plants, nothing more, nothing less. In hydroponics, water is simply used to supply the mineral nutrition and hydration required by the plants in order for them to sustain optimal growth and development patterns during their life cycle.

What hydroponics is really all about is control - control over how and when your plants take up water and nutrition. It is a big responsibility that leads to, if done correctly, a really big yield! So what are the advantages and disadvantages of hydroponics?

The Advantages and Disadvantages of Hydroponics

Hydroponics, although an excellent growing technique, still has its disadvantages as well as advantages when compared to soil based growing.

Some advantages of hydroponic growing are: faster growth, bigger yields, less damage from insects etc., greater control, higher quality produce and less water and fertilizer use.

The main disadvantages of hydroponics are the cost of set up, together with a higher level of technical expertise needed to maintain and run the hydroponics system. However, this technical expertise can range from very basic through to extremely advanced, it’s all up to the individual grower and their needs.

When summarized, the benefits of hydroponics far outweigh the negatives. However, don’t forget that hydroponics is a just a growing technique and can never remove the need for specialized knowledge of the plant or crop you are growing. Hydroponics will always serve you better if you have an understanding of the plant you are growing. Take time to understand the plant you’re growing; what conditions does it like? What pests and diseases may affect it? How do we quickly identify those pests and diseases? By building your knowledge base on the plant you are cultivating, you will, in turn, become more effective growers and can then experiment with more advanced techniques and concepts (if, of course, that is what you want to do). All successful commercial hydroponic farmers know their crop very intimately and have not only studied hydroponic cultivation but, more importantly, they have extensively studied the plant they are cropping. If they didn’t, they wouldn’t be in business very long.

One of the first things we need to look at is the hydroponic medium or the stuff we are going to grow our plants in. To get a good understanding of what a medium is and does, lets compare a hydroponic medium to soil, like the soil in your back garden.

Soil and Hydroponic Mediums - an Overview and Comparison:

Firstly, to be able compare soil and a hydroponic medium, we must first look at what essential and basic functions soil and hydroponic mediums perform. First, let’s look at soil. In a traditional garden, soil performs four basic functions for the plant;

1) It acts as an anchoring point for the plant (i.e. its roots)

2) Serves as a storehouse for food (i.e. mineral nutrition)

3) Functions as a reservoir for water

4) Acts as an interface between the roots and the stores it holds (i.e. the root environment)

In hydroponics, a medium also performs four basic functions for the plant;

1) It acts as an anchoring point for the plant (i.e. its roots),

2) Serves as a storehouse for food (i.e. mineral nutrition),

3) Functions as reservoir for water

4) Acts as an interface between the roots and the stores it holds (i.e. the root environment)

But hang on, I hear you say, they’re exactly the same functions! So, is there a difference or have you had too many consultations with your buddy Jack?

Well there is a difference, you just can’t see it yet, but it’s a BIG ONE!

Soil, just like rockwool, perlite or clay balls is, in actual fact, a medium too with the exception that soil is a dynamic living medium that constantly changes it’s traits or properties. This dynamism also makes it impossible to effectively control what happens in that medium (soil) with any degree of accuracy. Hydroponics mediums, on the other hand, are inert with static or fixed traits, except when you change them by changing your solution dynamics (nutrients, pH etc). Now, remember when I said hydroponics is really all about control. Ok, it’s now beginning to make a lot more sense. Now that we have established what hydroponics is (in a very basic way), let’s look at some popular hydroponics systems.

Different Types of Hydroponics Systems:

Essentially, there are three main types of hydroponics systems that are in use today. These are; Open Ended Systems (commonly called run to waste systems), Recirculating or Closed Systems and Static or Wick systems.

Open Ended Systems are those that do not reuse the nutrient solution applied to them and the excess applied is run off to waste. Hence, the common term run to waste. These systems are the most productive, as they provide the most control and feedback, although they are the least environment friendly. They are still a very popular system for commercial growers of large plants, due to higher yields, although this is changing via pressure from environmental lobby groups upon governments.

Closed Systems are those that re-use or recirculate their nutrient solution. These systems are very popular on a domestic level and for those commercial growers who grow smaller sized plants such as lettuce, strawberries, basil etc. Common examples of this type of system are; NFT (nutrient film technique), flood and drain (table top) and satellite systems.

Static Systems are those that draw up their nutrient solution from a small reservoir in the bottom of each container through the capillary action of the medium itself or, more commonly, through the use of a small wick that runs from the reservoir up through the center of the medium..

These systems typically have produced the lowest yields amongst all of the hydroponics systems and have lost popularity over the last 10 to 15 years and are now rarely used.

Well guys and gals, the bell is sounding for recess and it’s time to end our first lesson in Hydroponics 101.

Next issue we will be covering the very important and complex topic of pH, conductivity and the meters used to measure both.

So kick back take in what you have learned and get ready for the next issue as we learn how to get a handle on the basics of hydroponics and achieve that Maximum Yield!