A TALE OF TWO SYSTEMS
Nutrient expenses can be significant when the nutrient reservoir needs to be drained and re-established
every two to four weeks due to recirculation. For a
12-week maturity crop, this means the nutrient expense
can be anywhere from three to six times as high with
ebb and flow as with drip.
Set-up Comparison
The grow media used in each system has a big impact
on many decisions that need to be made regarding
both of these systems. Aspects such as initial cost,
ongoing cost, the recirculation effect on water quality,
and watering and nutrient scheduling for the various
grow media all come into play. Make sure you choose
the right grow media for your operation and then
design the set-up to match that. There is a ton of information on grow media on my reference webpage, a link
to which can be found at the end of this article.
In both ebb and flow and drip, the plants are usually
grown in pots. Because optimizing yield will require
larger and healthier roots, a drip system set-up must
utilize enough emitters to evenly moisten the entire
surface area of the grow media in the pot. The faster
the grow media drains, the more emitters the drip
system will need. With ebb and flow, the total grow
media volume is immersed in the nutrient/water solution each time the plants are watered, so the aspect of
thorough even distribution of water is easier to accomplish with the ebb and flow than with typical, twoemitter drip systems. In a drip system, there are some
special considerations to ma ke:
• Drip irrigation with few emitters – At the point
where water is applied to the soil or grow media,
and depending on the perk rate of that media, the
moisture area for the soil will likely look somewhat like Fig. 1. A slower application rate and/
or a dense grow media like soil or coco will also
spread the pattern out and apply a more thorough
application of water.
PLANT MAINTENANCE can
be easy or difficult depending
on how each system is set-up.”
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Maximum Yield USA | December 2016