There are variety of hydroponics systems and choosing which is best comes down to personal choice, well at least to a certain regard. The four main systems are the drip/sprinkler system, the flood and drain or ebb and flow system, the nutrient film technique, and aeroponics. But there is yet another that is little discussed or promoted, but from our experience has the best results while saving money and being more conscious of the environment—Top Feed Systems.

First let me explain each of the other techniques and then I’ll tell you about Top Feed Systems—how they differ and why they are the best bang for your buck.

1. The Drip or Sprinkler System: This system “involves dripping or spraying nutrient water around plant roots that are held in place by clay pellets, gravel, rockwool, sawdust, or peat mixes. One of the advantages is that the dripping or spraying nutrient carries a constant supply of air between droplets. In addition, the drips or sprays are timed to allow air-breathing cycles” (How to Supercharge Your Garden, 114)

The overall key to this system is that the roots must remain moist and if any of the drip systems get blocked or malfunction the roots can dry out very fast and the plant can die out very quickly.

2. The Ebb and Flow System: This system involves flooding the roots at regular intervals. There is a floodable area, a tray, that raises and lowers the nutrient rich water around the plant roots. The plants are usually held with some sort of soilless medium. The question that arises with Ebb and Flow is how often to submerse the plant’s roots within the nutrient rich water. “The reason for the flooding is only to keep the nutrient and air constantly moving over the roots.”(How to Supercharge Your Garden, 115) A good rule of thumb is to not submerse the plant’s roots for more than 30 minutes at a time and depending on the medium the plant is held in, this should be done hourly or daily. Problems with this system include, water pooling, standing water, pest problems, algae and mold. You must keep a close eye on this system.

3. Nutrient Film Technique (NFT): “is basically running a constant thin film of nutrient water across the roots on a sloped gutter or pipe. The film of water must be thin enough to be able to carry a film of air along with it. The roots are not held but each plant is supported in a collar with roots hanging into the gutter or pipe.” (How to Supercharge Your Garden, 116)

NFT systems are inconsistent in providing the right amount of water and nutrients vs. oxygen and can vary from plant to plant within the system. You must keep a close eye on the roots to make sure they are receiving enough oxygen. “The browner the roots are, the more they need oxygen.” (How to Supercharge Your Garden, 116)

4. Aeroponic systems use no growing medium. Roots are suspended in a dark growth chamber where they are misted with oxygen-rich nutrient solution at regular intervals. Only air and nutrient solution fill the growth chamber. Aeroponic systems require greater attention to detail but offer extremely high performance.

So we’ve gone through the most common systems used when growing hydroponically, but as I mentioned before there is one more that we at Hydroponics Unlimited have found to out do the others—the Top Feed System. Very similar to a drip system, but with Top Feed Systems, water and nutrients are fed from the top producing 10% more yield using 30-40% less water and nutrients — the greenest way to grow and the way Hydroponics Unlimited recommends. There are no major distributors of top feed systems , but at Hydroponics Unlimited we have begun building customized systems using state of the art materials that can turn any set up into a Top Feed System.

So I was flipping through a magazine the other day, and came across a great article on the “Relative Efficiency of Light Bulbs.”  We love hydroponics, but we’re always looking for information and ways of making hydroponics “greener” than it already is.  We started manufacturing Top Feed Systems for this very reason.  It has really cut down on our energy costs, which in turn helps the environment.  Anyway, back to lighting.  So it all comes down to lumens — measure of light intensity hitting a surface.  Household bulbs are measured in Watts, but when growing we care about Lumens (and lumens give us the most bang for our buck).  So they compared 6 types of light bulbs; incandescent, mercury, fluorescent, fusion sulphur, metal halide and high pressure sodium (HPS).  The 100 watt incandescent bulb shining 1 foot away from an object will put roughly 175 lumens, but 100 watt mercury will produce 600 lumens.  Put a 100 watt HPS bulb in the same circumstances and we’re talking 1,400 lumens.  So in conclusion High Intensity Discharge bulbs may cost more, but you’re getting a lot more bang for your buck and your plants will appreciate you more.  Lastly, here is the relative efficiency for the 6 bulbs types I mentioned above.  Incandescent: 8% efficiency; Mercury: 29% efficiency; Fluorescent: 38% efficiency; Fusion Sulphur: 44% efficiency; Metal Halid: 45-57% efficiency; and the big winner, High Pressure Sodium: 64% efficiency.  

Original Soure: How to Supercharge Your Garden

I stumbled upon a section on Co2 in the “How to Supercharge Your Garden” book written by Graham Reinders and illustrated by Marseene Mainly. I thought I’d share a piece of the chapter as it kind of made me laugh inside, but also displays our innate relationship with nature and the plants that we grow. See below and enjoy;

“People laughed when it was claimed that playing music to plants made them grow better.  It really did because the sound vibrations actually strengthen the stem fibers, shorten the internode length, and cause stress growth reactions  from the plants.”

(Go figure.  I wonder which genres produce best results.  It might depend on the plant…)

“Then people laughed when it was claimed that singing to plants made them grow better.  However, it is true.  The CO2 from human breath actually makes plants grow faster.  If you and a few gardeners stay in the indoor garden area during the light period, the plants would do very well.”

(So I’m not that crazy after all.  I knew my tomatoes loved a morning serenade.)

“It is thought that the massive plants that developed millions of years ago had lived in an environment with much more carbon dioxide in it.  In their evolution, the plants will maintained the capacity to use much more carbon dioxide than the world has now.”

(So create more CO2? Not so sure on this one…)

“Luckily in smoggy cities, the CO2 level can be as high as 500 PPM, and by just having a good circulating fan, the plants should have enough CO2 for a medium-light indoor garden.”

(Yes luckily.  And we’re located just outside of LA, so we’re very lucky!  So smog is good?)

“A high-light garden with the carbon dioxide amount increased from an ambient level of 300 PPM to a high level of 2,000 PPM can nearly double plant growth.”

(Bring on the Co2)

This book is a great resource and walks you through a number of areas dealing with both growing in general and hydroponics.  A must read for anyone interested in growing.

Check it out…

A pretty cool video from Discovery on growing Lettuce using hydroponics.

Grow tip of the week:  Keep your air temperature 10 -15 degrees lower at night.