Aquaponics is great.
And the flood and drain model is particularly interesting…..and useful.
But what if you wanted all of the benefits of aquaponics but none of the complexities of rearing fish?
Or what if you can only grow fish during a particular season? What do you do to keep your plants going during the off-season?
Well, there is a way….Vermiponics.
I first learned about vermiponics (a couple of years ago I think) through a post on a mailserve list by an American named Jim Joyner. He described his approach during a subsequent exchange of emails.
OK…..so how does it work?
Picture a basic flood and drain aquaponic system comprising a fish tank, a pump and a gravel grow bed or two.
At the risk of stating the obvious, you’d normally have fish in the fish tank…..but with vermiponics you substitute another ammonia source in place of the fish.
Most aquaponicists are aware that worms populate mature flood and drain systems and that they help to mineralise the solids in the grow beds.
In vermiponics, worms serve the same function except that their food source is something other than fish poop (like finely chopped vegetable scraps or rabbit manure)…..and rather than putting the food into the water, it is placed into the beds.
So, why would anyone want to do this?
The tilapia that Jim used to stock his aquaponics system, were only viable during the warmer months. His problem was that he needed something to power his AP system during the cold months.
Where most aquaponicists would simply look around for a cold water fish species, Jim (whose principal interest is in growing vegetables anyway) decided to trial an alternative ammonia source and rely on the nitrifying capability of the flood and drain process and the worms in his system to produce the nutrients for his plants.
He experimented with rabbit food before he realised that worms feed on microscopic life forms (rather than the food on which they grow) so he tried fermenting the rabbit food. Eventually, he arrived at the fact that the most efficient way to ferment the food was to put it through the rabbit first, so he started using rabbit manure.
OK…..so what are the advantages of vermiponics over aquaponics?
- The risk of catastrophic failure is much less.
- While worms need oxygen they can access it more effectively than fish.
- Worms will survive a power or equipment failure much longer than fish will.
- It’s much less expensive (in terms of energy costs) to run a vermiponics system than an aquaponics one.
- It’s much cheaper to feed worms than it is to feed fish if vegetable production is your desired outcome.
- Worms will also thrive on a much wider range of feedstuffs; many of which are so-called low value wastes.
- Worms will thrive in a much broader environmental range than fish will.
To summarise, when it comes to growing plants, vermiponics is cheaper, more efficient and is more risk-averse than aquaponics.
Some other thoughts:
Jim buries the food for the worms in a trench in the gravel grow bed.
Glenn Martinez (who lives in Hawaii) has a slightly different approach, He inserts a gravel barrier (90mm PVC pipe with plenty of 10mm holes drilled in it) into the grow bed and places the food source inside. He places a cap over the top to prevent vermin or sunlight from accessing the food scraps (worms are photo-sensitive).
Either flood and drain or surface-based continuous flow watering can be used. Timer-controlled flood and drain would be more energy-efficient particularly since the pump could be switched off overnight without endangering the system.
If you were to opt for continuous flow, you could get away with a much smaller (and much less expensive) container than a fish tank.
Either way, the water is going to be well-oxygenated…….which is good for the worms, the plants and the bacteria that drive the nitrification process.
It would be possible, through experimentation, to arrive at optimum worm feeding rates (and feed ingredients) for the plants being grown.
While vermiponics may not be the most effective way to grow worms for sale it could still be done. Placing a container of suitable food on the surface of the grow bed (while withholding it at their usual feeding spots) will attract the worms to the container which can then be removed to a bench where the worms can be sorted from their bedding.
The other possibility (and the one which led Jim to the whole thing anyway) is that a vermiponics approach may just be a useful way to keep plants going during the fish off-season…….whether that be in hot weather for those who grow rainbow trout or in colder weather for those who grow tilapia or jade perch.
Vermiponics is also a subject dear to Dr Brett Roe, a researcher at the Central Queensland University. He has been experimenting with various integrations of fish, crustaceans, plants and worms (in something he’s titled Vaquaponics) for several years. I had the good fortune to learn from (and share a platform with) Brett at the 2009 Commercial Aquaponics Course held in Brisbane.
Anyway, regardless of how it’s used (or where it first came from), it’s a very interesting idea and one worthy of further investigation. While it won’t replace aquaponics at Creek Street Micro Farm, it might become another means by which we grow clean fresh food.
-o0o-
{ 1 trackback }
{ 13 comments… read them below or add one }
Interesting stuff. Hope to see some technical data on this.
Ron B…….we’ll update our readers as new information comes to hand.
Fascinating. I’d love to see photos of this system. Can’t quite wrap my mind around how the system is constructed. Are photos of a system available anywhere?
Carolyn Allen…….in its simplest form, a vermiponics system is a basic aquaponics system comprising a fish tank (without the fish) and a grow bed (which contains the worms and the plants).
In an aquaponics system, you would normally feed the fish and the bacteria in the system would convert the ammonia that resulted from the digestion of that fish food into plant nutrients (nitrates).
In a vermiponics system, you provide a food source in the form of animal manure or vegetable wastes and heterotrophic bacteria convert the manure or vegetables to ammonia which is then converted by nitrates by autotrophic bacteria. The worms eat the bacteria and other organisms that thrive in the bio-conversion of the manure or vegetables and mineralise the wastes making the vitamins and minerals (that are bound up in the food) available to the plants.
The water in the fish tank is pumped up to the flood and drain grow beds……to irrigate the plants and distribute the nutrients. The ebb and flow action of the water in the grow bed pulls air down through the grow bed media (usually gravel or expanded clay pebbles) to the benefit of the worms, the plants and the bacteria. This aeration also prevents the water from becoming anaerobic.
I’ll see if I can find a suitable schematic diagram of a basic flood and drain system.
will african night crawler do will they not drawn
joserodrigo……..I have no experience of African Night Crawlers so I can’t comment of how well they’d go in an aquaponics system. Most of the worms that I’ve encountered seem to be ‘red wriggler’-type composting worms.
The conditions in flood and drain grow beds seem to suit worms very well given the numbers that appear in some systems.
anc are what we are using here in the philippines as composting worms can we combine vermiponics with aquaponics
joserodrigo…..worms will eventually move into a flood and drain aquaponics system. Most mature systems have them living in the grow beds.
Hello Gary and Thank you for sharing this precious information!
Do you know the rate between flooding and draining, in aquaponics made easy dvd I saw 12 minutes, what about vermiponics? And is any of the methods (constant flow / flow and drain) more comfortable for the worms?
JP…….you’re welcome.
For those situations where it is used, the timing of either of the flood or drain cycles isn’t that important. It will be influenced by whether you use timers or auto-syphons to control the pumping cycle.
For those situations where timers are used, a 15 minutes ON/45 minutes OFF regime is very common…..that is that the pump runs for 15 minutes (during which time the grow bed fills up) and then it shuts off for 45 minutes and the grow bed drains.
Where auto-syphons are used, the syphon itself will determine the rate of flow…….because they will only work within a given flow range…..and the pump runs continuously.
I use sub-surface continuous flow in my grow beds and, contrary to what some people say, they work fine.
As for vermiponics, I have yet to build such a system so I can’t say what happens there. I suggest that flood and drain would be useful to capture the mineralised nutrients that would accumulate in the worm part of the system…..to be transported to the grow beds.
Jim Joyner (an organic farmer from Tennessee is the person that I know who makes the most effective use of vermiponics in a practical situation. There are a couple of threads on his work on my forum……Aquaponics HQ.
Hi
I found this website over a Youtube Video of u..
Im experimenting at the moment with Hydroponics, mainly growing lettuce nd basil in a raft system.
And im also experimenting with vermicomposting.
I wonder about ur opinion of a short thougt i had in a diffrent aproach to the vermiponic technic..
What if i use finished vermicompost diluted in water in my raft growing beds? Instead of adding nutrient salts adding vermicompost..
Thanks for ur answer
Tom
Tommaldito…….we know, from research undertaken by Dr James Rakocy at the University of Virgin Islands (and others), that plants in raft systems don’t like solids around their roots. Having said that, Friendly Aquaponics report that they don’t remove solids in their micro systems.
Your use of “worm tea” may be different. Why don’t you undertake a small trial?
Thanks for ur answer gary..i will do trials nd will post the results in ur aquaponics HQ forum…
Greets Tom