Which type of hydroponic system is better?

Hint: They are all just irrigation systems.

One of the questions that I get most frequently is, “Which hydroponic system is the best?”

I am fairly sure that my standard answer of, “it all depends” annoys most of the people I am speaking to.  From suppliers to growers and from researchers to hobbyists there is always a desire to know and understand which system is the best.

So why do I answer, “it all depends”?

Whether we are talking about nutrient film technique (NFT), deep water culture (DWC), drip irrigation systems, aeroponics systems, ebb and flow systems, or any other system we should agree that these are all just variations of irrigation systems.

Buffer capacity means security.  Buffer capacity means you can leave for a day without fear of losing the crop.

Next let’s talk about the systems suppliers and their sales representatives.  Suppliers of hydroponic systems will all tell you why theirs is better, but the conversation should really revolve around what factors cause their systems to fail.  Every system has a weakness.  Your crop, your budget, your facility and your geographic location will likely quickly highlight these weaknesses. 

So, how do you determine what system is best for you?

Here are the things you should know, think about and research thoroughly before you invest.

1. What crop are you going to grow?  If you are planning to grow tomatoes, it’s very unlikely that you will want to invest in a nft system or a dwc system.  The needs of your crop will help direct you into the right direction.  Likewise, a closed loop drip irrigation system is unlikely to be the answer for lettuce production.
   
2. Know your budget.  Your budget will play a major role in this decision making process.  Do not only think about the upfront costs of the system.  Make sure to include the operational and labor costs associated with running the system 7 days a week 365 days per year.
   
3. Know your environment.  Each crop type will respond to these 9 environmental variables (see diagram below) in different ways.  As a grower your ability to manage these variables will be a primary indicator of your ability to achieve your target yields.  The irrigation systems primary function is to help you control the 4 variables surrounding the root zone (see diagram below and focus on root zone temp, nutrients, water and oxygen.) Your geographic location and crop will determine which of these variables are most important. 
   
4. Truly understand the design.  In the recent Urban Ag News article, “Important Tips For Designing A Hydroponic Production Facility” I discussed the importance of buffer capacity.  Buffer capacity in your irrigation system plays some very important roles.  First, it will help you manage your nutrients.  Second, it will help your crop deal with variations in temperature. Third and most importantly, it will be a primary indicator of how much time you can spend away from your farm.
   
5. Figure out your maintenance and spare parts plan.  Irrigation systems break.  Irrigation systems get clogged.  Irrigation systems need to be serviced and fixed.  Make sure you understand everything from how to access the most vulnerable and weak parts of the system to how long it will take you to get replacement parts and what parts you should plan to carry in case of an emergency.  Think about redundancy!

Labor is KEY! Consider every aspect of labor.  From the education requirements of running the labor, to the amount of labor needed to operate and maintain the system to the importance of labor needed to check on the system on a regular basis.
Budget • Scale • Access

Which brings me back to where we started.  Which hydroponic system is the best?  It truly all depends.  All we know for sure is that if a supplier tells you, “you can grow every crop in our system”, be concerned.  It might be true, but I can almost guarantee you that you cannot grow every crop profitably in their system.  If a supplier struggles to help you clearly understand and answer the questions posed in this article, look for a new supplier.  There are plenty that will. 

Finally, focus on building a professional network with experience in the commercial hydroponics industries.  Ask lots of questions and understand the full benefits and limitations of any system you choose. 

Final hint: Aquaponics growers use one of these systems as well.