I saw that comment Pakman Aquaponics can use lots of power on pumps and I have grave concerns on the nutrition of foor grown on fish poo without access to the enzimes and fungi present in soil and available to plants grown in good organic dirt. I love the way it closes to loop so to speak and will have applications where agriculture is not viable. The protien raised is a valuable contribution to the function stack though as a vego it does little for me.
I understand your concern my friend from across the great sea.. but I leave you with this Aquaponic system to consider. [video]https://youtu.be/jV9CCxdkOng[/video] 1,000,000 US pounds of food, 300 to 500 yards of worm compost 10,000 marketable talapia per year All of which grows year round, non-profit, in a harsh snow riddled area.
it does show potential! I remain concerned by the cost and impact of the infrustructure required to achieve the results - the pumps and pipes and poly but it is sexy for sure.
Using worm castings would be ideal. Just dissolve them in water and strain off any remaining solids through shade cloth. What you have is nuitrients that are ready for the plants to take up. If your system is small enough fill the whole system with Worm Juice and then just keep it topped up. You can brew some Worm Tea by mixing castings in water then adding some seaweed /kelp fertilizer to feed the fungi in the castings, mollases to feed the bacteria. Add a air pump with some air stones to the bottom of the mix and let it bubble for 24/48 hours then use it. I would add the air stone into the system somewhere to keep the oxygen levels up. A small pond pump would be all you need and it would use very little power. Set up the pump in a container/sump at the bottom of your system. Make sure it is big enough to hold all the water in the system in case of a power failure. I would top up the system from there. To get lots of castings you need lots of worms and the can of worms system probably wont cut it. I breed in tubs and hold about 4,000 to 12,000 worms per tub. This many worms will eat out any bedding very quickly thus filling your tubs with castings. Management is the key with the worms. It is very easy if you follow some simple guidelines.
People are already doing interesting work with exactly that idea. https://www.fijilettuce.com/ Using coconut coir as a growing media and humus and worm casting tea as fertilisers allows Fijians to grow their own healthy fresh salad veggies. This may not be 100% sustainable by everyone's definition(what inputs don't they mention) however it is a step in the right direction. Some people in remote communities don't have access to fresh food that some of us Westerners take for granted, who are we to tell them they shouldn't use this technology. Back to the topic of aquaponics, I noticed a previous poster describe it as a closed loop system. It don't see how? The grower needs to constantly feed the fish and often with a commercially available fish pellets. Where are these sourced from: -fish meal harvested from the sea (food miles & over fishing issues) -contains soya beans (GM enhanced) -land based animal free? I'm not claiming any horticultural system is either good or bad it is more the application as the old saying say the Devil is in the detail.
I remember seeing a system that had chooks over a swimming pool and the fish ate the chook poo. Not 100% sure if they were still using fish food, but there would be a way to design a closed loop.
I have seen many, but when I learned from the Permaculture Designers Manual how many chooks per sq. foot of pond, I passed on the idea.
Don't forget that the nutrients in food only come from what their plant roots can get. Just like baby greens don't have as much nutrition in them as mature greens, aquaponics or hydroponics don't ever offer as much nutrition as healthy, organically amended soil. Just because food looks good, doesn't mean it's got what we need in it. Chemical fertilizers make food look great, too, and look what you get from that....
I would have thought aquaponics is a healthy, organically amended soil. Its organic, has worms, bacteria, a structure of clay balls sands or rocks and is fertilised by natural manures.
Missing minerals that are present in soils. Also missing contaminants too. And I suppose some soils have too many minerals, or not enough, or the wrong type, so we are doomed whichever way we go about it.
If you used gravel as your medium you would get some of the minerals depending on the varieties. Worms in your beds would be working the minerals through too. The diet of your fish would also determine the mineral content in the beds.
Yeah, some. Definitely not the whole gamut of soil minerals though. What about mycorrhizal relationships too, exchanging minerals with fungi? I'm not saying anything negative about aquaponics, don't get me wrong.
But again, the minerals that mycorrhizae are adapted to harvest may not be present in poo and a monoculture of substrate. This was just expanding on sweetpea's post. I'm reminded about the Nursery Manager at my work, talking about chemical fert and organic. He stated that the plants don't know the difference, I stated that the soil knows the difference and that I know the difference. Maybe they don't, maybe they do. Maybe our nutrition relies on minerals, maybe it doesn't.
The only reason I have not started my own aquaponics is the set up cost and the need to constantly buy new baby fish. That would make me dependant on a fish farm over 2 hours drive away. Ok now, as it adds $60 or $70 to my annual fish bill, but it doesn't take into account if that business will still be here in 5 years and the price of petrol. To make it sustainable you would need a fish that bred freely and ate anything and tasted great. There are tilapia growing wild in the dams around here,but its illegal to have them in your aquaponics set up.
bugger! I don't like the taste of freshwater fish which is why I haven't gone down the track of investigating aquaponics for my disused pool (which at the moment has 3 different types of tadpoles, eastern sedgwick, graceful treefrog and green treefrog). A friend had a dam ful of silver perch in his dam and they tasted like crap. Good if your wanting protein though and you have lots of garlic, chilli and soy sauce. Even the freshwater redclaw has to be bombarded with herbs and spices to be edible.