Aquaponics in Japan - Feedback on design for Community Group?

[Japan Aquaponics - アクアポニックス 日本]

Hi there everyone,

Recently we have been working with a small community group that was seriously affected by last year's earthquake here in Japan. We have been talking about helping them to build a backyard-sized aquaponics system into their community garden to provide an activity for both children and elderly people.

Some of these individuals are still facing mental and emotional difficulties after last year's events and so the hope is that a community garden will be therapeutic, as well as providing a great activity for everyone, and finally they can either eat their own produce or run a small market garden or something like that.

We are trying to put the system together as simply as possible so there is nothing fancy or clever here. It would be great if you could take a look at the plans that we have posted and let me know your thoughts and/or suggestions. Anything would be most welcome.

http://www.japan-aquaponics.com/ANZCCJ-Tohoku

Here is a screen grab of the design, but please check out the link for the accompanying details of the design and tell me what you think.

Thank you,

Aragon

[Jonathan Kadish NYC AA Chair]

I haven't seen the SLO before, is it proven or a new idea? I would imagine you will need to figure out what rate of flow or size pipe the SLO needs to be to overcome gravity when lifting the solids. I have thought about putting a blender type mixer, or a paint stirrer thingy into the solids area to have the solids completely in solution, just flick a switch when it builds up. The only other thing I see is spreading the effluent equally over the grow beds will be something you need to account for... the first bed will get most of the poo and could get anaerobic. Consider 2 beds side by side at the same height.... My 2 cents :)

[Japan Aquaponics - アクアポニックス 日本]

Thanks Jonathan, good point for the distribution of the solids between the 2 beds.  The SLO is quite commonly used I thought - it is just a pipe that sits in the tank down to almost the bottom and then out of the side of the tank - with the water flowing into the fish tank the only exit is then through that pipe and so the solids.. which will usually fall to the bottom will just naturally be carried up that pipe and out.

My understanding is that solids should ideally not be turned immediately into solution as the increasingly small particles would not be taken out by the grow beds and so they would end up on the roots of the DWC.  I believe that the smaller suspended solid particles can also potentially reduce the oxygen levels in the water.  If the worms can take care of a lot of the mineralisation then that leaves less feed for the heterotrophic bacteria - and they need oxygen to do their thing - so the more of them there are, then the less oxygen you will end up with.  I think that sharper minds than mine can add to that idea.

Will look at the idea about spreading the poo though... that could be a good change and easy to make.  Thank you!

[Jonathan Kadish NYC AA Chair]

We definitely think alike - this system is similar to what I plan to to for a small commercial operation (Again you beat me to the punch!). I would love to just do UVI DWC but I don't want to deal with removing solids all the time and storing them for terrestrial fertilizer.  So the natural solution is grow beds with worms as the way to get to the DWC. Without DWC commercial applications will have a hard time making a profit.

Oh, one other thing. Your system doesn't show the air supply. You will need air stones in each element of the system of course, but I'm sure you knew that. Designing that will take some learning and alot of 3/4 or 1/2 inch pvc. Nelson & Pade does air stones in their media bed at their demonstration greenhouse so we know it works.

[Japan Aquaponics - アクアポニックス 日本]

Hey Jonathan,

I agree about integrating the media beds with DWC - seems a shame to waste those nutrients, as well as a chance to grow a wider variety of plants, and with less manual solids removal.  

With regards to the aeration... I tried to show some in the sump tank, and had noted on the webpage that I may need to add it into the DWC.  I have been doing a little more reading and whilst I think that the system would work without the additional aeration in the DWC it is clear that if it were added, the plant growth would be significantly enhanced.

In the back of my mind with this design was the idea that the greenhouse could be integrated with flexible Organic Photovoltaic Cells and could be almost entirely self-sufficient and sustainable.  This is why I was trying to keep passive aeration up and mechanical systems down.  It may not be possible!  We will see what can be done though, but I definitely need to think about how to future-proof the design so that aeration can be added if necessary.

[RupertofOZ]

Hi Japan Aquaponics... Looks like a perfectly standard "hybrid" media grow bed/raft system design... and should work just fine....

Although, I don't see the need, or benefit in having the grow bed(s) cascade into subsequent grow beds... just plumb them inline with a common water distribution... (it makes life easier than trying to match flows to initiate siphons etc) ...

 

And Jonathan... the "SLO" ... solids lifting overflow... is the heart of "Chift Pist"... or "Chop" as it was rebadged, and subsequently "ChopII".... and has been in operation and proven for many years....

 

Basically this design is exactly what is intended to be demonstrated in forthcoming "training workshops"... although that design proposal will probably utilise a "ChopII" variation... where the sump water is pumped both back to the fish tank, and to the grow beds at the same time...

 

 

[RupertofOZ]

As a further suggestion.... perhaps you could investigate the concept of running your media grow beds as "constant flood"...

 

Aeration would be a critical factor if doing so... but aerating the fish tank,and DWC troughs .. (and/or the sump).... would be advisable regardless of what methodology you employ...

[Japan Aquaponics - アクアポニックス 日本]

Hi Rupert,

This design is indeed based on constant flood - after I saw the research done at BYAP I felt much more comfortable with that type of design.  If you have a chance to look at the webpage there are some notes on the system and the design.  Sorry they are a bit long - but basically it does outline a CHIFT PIST and grow beds set up in a Constant Flood manner.

[Japan Aquaponics - アクアポニックス 日本]

Oh and the varying heights of the grow beds were to allow younger children, or wheelchair users to have easier access to at least one of the beds.  I thought that the drop might also add a small amount of additional aeration into the system.

[Jonathan Kadish NYC AA Chair]

I watched this video uploaded by Murry Hallam of Dr Wilson Lennard that gives a enlightening explanation of just why and where DO is needed.

http://youtu.be/OkeUZl4_k3s

[Japan Aquaponics - アクアポニックス 日本]

This is a great video... I really like the presentations by Dr. Lennard... he has a few and they are all really well worth checking out.

[TCLynx]

If you are going to bother with Raft beds, Definitely make plans to put aeration into them.  So far everyone I've heard experiences from has noted how the plants grow sooooooo much better where there is good aeration to the raft beds and the plants languish where the aeration is not adequate.  I have experienced that too.

I find that media based aquaponics growing elements seem to do better where there are any water chemistry difficulties.  Or at least with water chemistry difficulties like mine with high pH and lots of calcium carbonate in my water.  My hard water tends to keep a pH up around 7.6 and the plants in the media beds still do well but the plants I have tried in rafts and NFT will show the Iron deficiency and/or potassium deficiency (because of too much calcium) far more than the ones in the gravel beds or the Zipgrow towers.

[Japan Aquaponics - アクアポニックス 日本]

Thanks TCLynx,  I am in agreement about the need for aeration, and think that during the hot summer over here, it would definitely be necessary.

I am not sure of the water composition in the area that this might be installed, but can find out easily as the city offices post all of this information online every week in Japan (although that might just be because of last years events).  Will definitely think about that though.

I realised one error in the system - there was no overflow pipe from the fish tank... on the very odd chance that the SLO became blocked.... highly unlikely I know, but no harm in adding it in from the beginning.  Just a simple direct overflow from the FT to the 1st GB.