Aquaponics 101 – NFT, what I’ve learnt.

In Aquaponics 101 – NFT I introduced the concept of NFT, or Nutrient Flow Technique and demonstrated how to build a simple Aquaponic NFT cylinder out of 110mm PVC pipe.  This posting is a report back on this system (after about 2 weeks) as well as about some things that I have learnt about NFT since then.

First the report back. To test the concept I planted the following;

  • Lettuce seeds directly onto the wick in the yogurt cup.
  • Lettuce seedlings that had been germinated in seed trays.
  • A fully grown mustard lettuce plant with some roots through the bottom of the cup.
  • Two small strawberry plants.

The lettuce seeds germinated immediately and have grown faster that seeds planted at the same time in seed trays. I find this quiet amazing because they are only getting their moisture (and nutrients) from what is sucked up by the wick from the water flowing in the pipe. Here is what the little seedlings look like now.


The lettuce planted from seedlings has also done well but to varying degrees. I think the two plants that didn’t make it were probably planted away from the wick and just dried out. But anyway this is what 3 of the survivors look like.


The reason I planted one fully grown mustard lettuce plant was to see how the roots handled being mostly submerged in water 24/7. Remember that I am also applying aeration by means of a slinky airstone to the NFT. As you can see the roots have grown like crazy and shows no sign of root rot. (that dark colour is solids build up)


Something I have learnt, and you can see from the photograph, is that some sort of pre-filtering is necessary because of the solids build-up on the root mat. Once all the roots are established like this plant, I believe that the NFT tube will clog up altogether and in fact overflow from the build up of solids. Using pre-filtered water will also result in much cleaner roots. If I was going to incorporate NFT into an existing gravel-based flood and drain system, I would place it AFTER the gravel to reduce solids build up.

Secondly, the aeration is great and will give you extra insurance against root rot. Using a blower and airstones may be a slight overkill but any extra bubbling will help.

Thirdly, the secret is to get half the root mat developing out of the water and the rest in the water. The flow of water in my NFT tube is too deep and is flowing too fast. I have now taken the endcap off of the outlet, elevated the tube more (ie. it now slopes more) and I am also going to slow the flow, probably by introducing a bypass.

Lastly, another thing that has become apparent is that a tube-based system may be too expensive to make NFT in Aquaponics commercially viable. This is because the capital cost per plant bay is very high. To prove the concept is great, but there are surely cheaper ways of achieving the same goal. I was recently invited to view a pilot site that incorporates NFT and found them using a brilliant idea of plastic roof sheet as water throughs and corex sheets over the top with lettuce planted through little holes. Here is what it looks like. I’ll be making one of these real soon.


Anyway, enough for now.



4 thoughts on “Aquaponics 101 – NFT, what I’ve learnt.”

  1. Just getting started in aquaponics. Am currently building a 190 l system using blue barrels to learn from. Thanks for the faithful posts.

    Even the political side trails are understandable. The U.S. Southeast went through similar unrest, pain, and outright political foolishness right after the U.S. Civil war. *(not writen about in too many books because the winners of the wars write/rewrite the history books) We are currently experiencing a sort of (at present mild) aftershock of that temblor. The only ones that profit from any of this and the only true enemy are the ridiculously wealthy. The truly sad note is that oft times one group of poor servants to these modern day fieflords usually end up as human walls against another group serving the same masters. The fief lord steps in collects the spoils, sets up poor ignorant servants who think they have won some victory and set them to serving them as before. On rare occasions they may be inconvenienced but it is truly rare indeed that the true enemies are overthrown. The way of Newtopia is best.

    -Separate but aware.
    -Creativity tempered by wisdom not foolhardiness.
    -Wisdom, for intelligence by itself is good only for impressing the simple, The wise quietly seek to broaden their knowledge but the intellectual often loudly avoids wisdom at all cost.
    -Compassion without susceptibility to parasitism.
    -Sufficiency with enough excess to provide those things which cannot be provided from within and for calamity.
    -Potential beyond sufficiency.
    -Preparedness to make use of additional potential.
    -Caution to survive but not enough to cripple with hesitation.
    -Willingness to do …
    -Strength, not necessarily to fend off failure, but definately enough to get back up, accept that failure has happened and try something different until it doesn’t.

    That is just a short list of the “philosophical” guidelines of such a society pulled from my own blog. It sounded like they might fit with some of your own views on the subject.


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