Holy grail for aquaponic production

[Kobus Jooste]

Which plants are still considered "difficult" or "impossible" to grow in aquaponics?  I have begun a process of trying to design a system that can grow as many different varieites of crop possible.  Only a few years ago, pundits declared aquaponics "only suited to growing leafy greens".  That has been proven incorrect over and over, but is there any plant people still consider as being impossible to grow in aquaponics?

[BenHehle Beamz]

hard to find an answer :D has anyone tried peanuts yet or pineapple?

[David Waite]

would have to be the potato. I know you are trying this but I havent cracked that nut yet.

[Kobus Jooste]

Benhehle, I'm not sure about peanut or pinapple - must say I never thought of those two. Pinapple is perhaps a lot of investing in a plant for one fruit though.  Peanuts could be interesting to try, as they are very nutritious.

 

David - yes, I'm going after potato because I see a system capable of producing tubers, bulbs and roots as vital in addressing poverty issues in Southern Africa.  I want to be able to take aquaponics from a niche market producer to the community garden level where everything the community needs comes from the system.  I think I should add peanuts to my list.  

[Sylvia Bernstein]

OK, Kobus...here is a stumper for you. I typically tell people that they can't grow acid-loving plants like blueberries in AP.  Any chance you can figure that one out?

[Sahib Punjabi]

Namaste Kobus,

 

I am in due course, possibly next year and if I can get the seeds), going to experiment growing Rice. Then I will try Sweet potato as well different grains such as Wheat/Barley/Oats etc.

 

If anyone has already tried, please share.

 

Will share results then  :-)

 

God bless,

[TCLynx]

I have done several root crops just fine in Aquaponics.  Biggest issue with roots in media beds is less to do with the media and more to do with too much water or the roots pushing so hard against the media that they could bulge the bed.

 

Sweet potatoes are easy but they tend to form more potatoes where the media is dryer, (I had a kinda wet wicking bed where I grew sweet potatoes this summer and more potatoes formed where the vines left the bed and sent them down into the mulch and dryer sand.  Odd since sweet potatoes like lots of water but I guess they need it well drained.

 

With regular potatoes, you might want to do something where the initial seed potato is down where it gets the irrigation from flood and drain but then mound up a light weight media as the plant grows so the new potatoes will form in dryer media.  I know of people who have grown some potatoes in aquaponics.  This might be a good use for perlite, vermiculite or sand.

 

There are of course the strawberries that we know can grow in aquaponics but many people find them really challenging, especially in a new system probably due to pH and salt.

 

Blueberries would probably be impossible in a new system or high pH system but I know of systems that tend to run rather low pH and perhaps blueberries would be possible there.

 

Peanuts.  I haven't tried it yet but I do have a good climate for growing them through the long hot summer so perhaps I need to try them sometime.  They are probably another one that would be good for the sand, perlite or vermiculite beds.

 

Pineapple would be fairly easy to try.  I have tried it but not all of them take and I think the one I had in Aquaponics got killed by last winter's freeze.  They are kinda a prickly space hog for aquaponics though, might be better to use in the dirt landscape.

[TCLynx]

The Holy grail I think has more to do with figuring out what to grow and in what quantities to provide a nice balance for the family without having a glut of things you don't eat enough of and always running out of the stuff you want all the time while still having a good balance of nutrients to plants.

[Kobus Jooste]

Sylvia - what pH is supposed to be ideal for blueberries?  Potatoes are also supposed to be acid loving but I have managed to keep one going for around 3 - 4 months now. In my hybrid system, I have observed vey low pH over an extended period of time (6.5) without it crashing.  I think that is close to the lower limit of aquaponics though.  There could be a trick in using silica sand though.  Sandy soils in South Africa are typically acidic, but perhaps you could keep an acid loving plant happy by having it at the lowest pH you can manage and in quartz sand.  Part of what makes aquaponics interesting to me is that we see a lot of plants doing something they are not supposed to in terms of the environment we have and the types of plants that thrive.  I think every plant has a medium / light intensity / flooding regime / pH compromise sweet spot - the trick would be to see how many different crops can be accomodated in a single system.  I do not want to end up (for me in any case) with a system for this and one for that.  I want one system, a whole lot of environments, and a whole lot of crops.  I'm putting my money on sand, gravel, raft and tower being able to do all of that.  You are just going to be looking at a few pumps in order to alternate flooding regimes.

Sylvia Bernstein said:

OK, Kobus...here is a stumper for you. I typically tell people that they can't grow acid-loving plants like blueberries in AP.  Any chance you can figure that one out?

[TCLynx]

Some people run even lower pH Kobus.  I'm not sure how they do it without problems but they have been for ages.  (Joel At BYAP)  I guess if you let the bacteria get used to a pH range and keep an eye on the ammonia to make sure it doesn't start spiking, then it works.  Might also be the tap water they have there lets them get away with it I don't know but I think He has systems that have consistently run in a pH range between 5-6.  They add shell grit when they see signs of calcium deficiency.  Might want to ask them for more details there.

 

I know whit my systems if I let the pH drop below 6 I usually see the ammonia start rising so I try to keep them buffered to at least 6.5.  Might be something to do with the fact that my well water will bring the pH up way higher when I have to use it for top ups so the bacteria has never had enough time to really settle in to the lower pH range.

 

As to what pH is ideal for blueberries.  I've seen one thing that said 4-5 as the pH for blueberries.  My soil pH last I had it tested was between 5-6 and I'm growing blueberries.  I mulch them with oak leaves and pie needles and feed them azalea fertilizer and they have done fairly well for me in my soil.

 

Now the truth is almost all plants growing in aquaponics are generally growing outside their optimum pH range so I'm fairly certain it is possible to grow most any type of plant in aquaponics though some systems might not work for certain specific plants.  (my high pH system I won't even try strawberries or blueberries in that.)

[Sylvia Bernstein]

Kobus, I think this is a fascinating initiative you are taking on and I wholeheartedly agree that the key is to find how many combinations thrive in the same ecosystem....and I've noticed the same thing that there are a lot of "common knowledge" rules out there about growing plants that AP seems to happily ignore. Thanks for the inspiration - I think I"ll order a blueberry plant today!

Here is a link to an article about growing blueberries - http://www.ces.ncsu.edu/depts/hort/hil/hil-8207.html - looks like 5ish is an ideal pH.

Kobus Jooste said:

Sylvia - what pH is supposed to be ideal for blueberries?  Potatoes are also supposed to be acid loving but I have managed to keep one going for around 3 - 4 months now. In my hybrid system, I have observed vey low pH over an extended period of time (6.5) without it crashing. ... Part of what makes aquaponics interesting to me is that we see a lot of plants doing something they are not supposed to in terms of the environment we have and the types of plants that thrive.  I think every plant has a medium / light intensity / flooding regime / pH compromise sweet spot - the trick would be to see how many different crops can be accomodated in a single system.  I do not want to end up (for me in any case) with a system for this and one for that.  I want one system, a whole lot of environments, and a whole lot of crops.  

[Chris Smith]

I have been trying for a long time to get spinach to grow well in AP without success. I have tried many varities and techniques. I thought that with how easily other leafy greens grow that spinach would be the same.I know many others who have had similar results as me in this area. There is a good market for here for spinach so I have spent a lot of time trying to develop a good technique.

Pineapple will grow in AP. I regularly put tops into a raft to let them grow good roots before planting them in the ground. I cannot justify tying up system space for a plant that fruits once every year or so. I let one go for 6 months and it grow very big with roots that were beautiful when I planted it.

[TCLynx]

I remember doing some research into trying to grow spinach hydroponically years ago.  It is a notoriously difficult one to get reliable germination when seeding hydroponically.

 

I've had great luck with it when planting in soil/compost but I too have had difficulty getting good results in aquaponics.  I'm currently trying to start some spinach in pellets now for the towers since I too think it would be a good product.  Crazy since beets and swiss chard do so well in aquaponics, one would think the close relative spinach should be easy too.