Comment

Comment by Jesse Hull on January 5, 2011 at 3:48pm

I've experienced much better growth rate when using ebb & flow as compared to "deep water" NFT in both small and large hydroponic/aquaponic systems. NFT is supposed to be a film of water, mostly unvaried in its depth down the entire length of flow.  The longer and wider the grow channel gets, the harder it is to achieve a consistent water depth.  Even if you can create a level plane, age will change all of that, and by the time the water gets to the end of one of our 20-40 foot plant runs, it is pretty depleted of oxygen anyway.  Aerating the water in the plant beds (as in Deep Water Culture) is an option; however, this adds the expense of buying and powering another piece of equipment, as well as the risk of that equipment failing.  On large systems like ours, I believe that another cost/risk is just one too many.

A correctly timed ebb & flow set up provides a wonderful supply of water and nutrient, without the concern of "drowning" the rhizosphere.

Comment by Two Jay on October 6, 2010 at 11:54am

Why the big change from constant flow to Ebb & Flow? FYI it looks like my wife and I will be visiting next weekend.

Comment by Jesse Hull on October 6, 2010 at 10:45am

Yes, these are the seedling stations in our propagation room. It's changed just a bit since this pic was taken, but it is still an ebb&flow (flood&drain) system.
On that note, we're currently preparing to change our clarifier/bio-filter set up to accommodate an ebb&flow watering approach as opposed to the constant flow of effluent water in our larger systems.

Comment by Two Jay on September 23, 2010 at 11:26am

Jesse, Is this bed included in the AP system? If so, I assume it is Flood and Drain since there is not any water present.