To have a successful aquaponic pond it seems possible but one would have to overstock heavily to provide ample nitrates to supply growbeds with enough excess nutrients. It could be done but I'm not the expert to say just how much loading or grow bed area required to make it successful.
Hi Charlie and others interested.
Aquaponics is just a big bio-filter with plants in it really. It's an easy learning curve for fishy folk, just the plumbing stuff which you'll know some of, and choosing what you want to eat to plant. Backyard aquaponics has a wealth of info about all sorts of AP related subjects.
The 1:2 ratio for water/growbeds in backyardaquaponics systems is merely a guideline for removing wastes under highly stocked conditions.
1000 litre aquaponic pond stocked with 30 plus kilograms fish might require 2000 litres of growbed.
But 20 000 litres pond with 30 kilos of fish will only require 2000 litres of growbed as well. Just circulate the pondwater through the growbed and nature will take care of the rest. At 300 mm (recommended) depth this is approximately 7 m2 garden area (dodgy math). This would supplement a family's household food well with the most delicious vegetables and herbs while simultaneously keeping the above mentioned ponds so clean they require no maintenance.
For ponds that already use pumps this is a great way to take advantage of the circulation of water to recycle the wastes. You could even feed the garden to soldier fly larvae and recycle it all back into the pond as high quality protein.
I've also has success in having a 'double' layer of beds, the first grows fruiting veggies and the water from this goes through a watercress bed. This needs only 10 cm medium and when it's warm it sure cleans the water up (and grows) fast.
Adding a 1/2 m2 watercress bed (nasturtium officianale) reduced a 600 litre pond system running at a constant 60 ppm nitrate to 5 ppm nitrate within a week. The pond has about 3/4 kg goldfish in it. I feed them fairly light, the pond runs clean now with approx 300 litres medium.
That's 2:1 pond:growbed ratio instead of a 1:2. When I had less fish I just had less beds. 3:1. 4:1! I first kept it clean with a 50 litre bed and a tomato plant. Of course the vine ended up 30 feet long a year later. 200 tomatoes before christmas.
A ROUGH guideline I use, 1 kilo of fish per 100 litres growbed. If you feed heavily for raising out fish fast you might want to raise that to 1 kilo fish per 150 litres.
Note: The garden needs reasonable light period for photosynthesis. The plants growth removes the wastes. The better the light, the better the growth, the better your filter.
I use small continuous flow pumps and auto siphoning beds. One moving part, minimal power consumption.
Coho??? , that was the answer in aquanic. 