Active Hydroponics

by Jenna Marshall

The options in active hydroponics can be mind-boggling. They are much more complex than their passive cousins, and more expensive, but it is possible to grow strong plants with most types of active hydroponics.

The term active refers to the nutrient solution, meaning there is some piece of equipment that is moving your solution, or pumping it full of air. It can be much more complicated than that, but you get the idea. Options can include an air pump to put oxygen into the nutrient solution, a water pump to move the solution from one place to the next, timers to keep everything on schedule and so on. The options are endless.

The most common types of active hydroponics are the Nutrient Film Technique (NFT), Ebb and Flow, Top Feed, and Aeroponics. I would recommend that you experiment with active hydroponics before you go to a great deal of expense. Try to start simple and get a few successes under your belt before you make a big investment. The preparation is worth it.

With NFT, the roots of your plants are suspended in a tube and the plant is held up by a support collar or basket. The nutrient solution is in a reservoir and is pumped into the tube from above. The solution is fed over the roots, and it drains back to the reservoir. There is a constant flow of solution. This is a tough one for the beginner. This method uses no growing medium, so moisture drains away very quickly. If the solution is interrupted or you have an equipment failure, you will quickly have a bunch of dead plants.

EBB AND FLOW

Also known as the Flood and Drain method, this is a popular method. This is also a great place to start if you are a beginner at active hydroponics. Start with a reservoir of nutrient solution (properly pH balanced, of course). Put a submersible water pump with a timer in the solution. Above your reservoir is the grow tray of medium (quickly draining) and plants. The tray will start with two holes – one connected to the pump hose, and on to drain the solution back to the reservoir. Set the timer to turn the pump on several times a day. If you have a larger set up, you will, of course, need more pumps and more drain holes. This technique is fairly low cost and low maintenance. It is a good method for uniform growth, and for seedlings and transplants.

TOP FEED

This method is good for most all plant types. It generally works best on a large scale and is very versatile. You can use virtually any type of growing medium. However, this version tends to get expensive.

Similar to Ebb and Flow, with this type you again have a reservoir with a water pump and timer. As the name suggests, the nutrient solution is pumped to the top of the medium, and gravity drains it back down to the reservoir. Getting good coverage to each plant is sometimes a challenge here. Once you have worked the kinks out of your set up, this is generally a reliable, low maintenance method.

AEROPONICS

This method is hugely popular right now. There are many prefab units popping up for home use. All the equipment is set up and is lower maintenance than home-made models. This makes them more cost-efficient and easier to use.

Basically, aeroponics is where the roots of the plant are suspended in an enclosed chamber. In that chamber, the nutrient solution is misted in to coat the roots. This is an oxygen-rich environment, so the nutrients are easily absorbed. To create the mist will require compressors, air pumps, and sprayers. This is a great method for propagation, but is best on a small scale. It is extremely high maintenance, and can be expensive.

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