Backyard Aquaponics
A place to discuss aquaponics

There seems to be a trend particularly among the bigger scale and probably more experienced members to move towards de-coupled systems.
As I understand it.
The fish side generally incorporates mechanical filtration and DWC seems to be the preferred method of crop production.
A move away from the media GB and incorporated filtration.
The ability to run different water parameters is to me the most obvious benefit.
Are we really saying that , ‘hydroponics’ is a better method of producing crops and therefore fish are a very useful producer of additional nutrients?
At what size does this , de-coupling , become more efficient?
On balance I am leaning towards de- coupled but would love to hear your views.

There are a dozen or more large scale, and two very large scale commercial operations I'm aware of that are operating very successfully and don't run de-coupled systems. They run hybrid systems with a combination of DWC and media beds. Many of them have only been built in the last two or three years, so were fully aware of the recent trend by a small number of operators to go de-coupled, but still chose to run dedicated hybrid aquaponic systems.

One of these operations has captured 10% of Hong Kong's organic produce market in just two years... Practitioners of the de-coupled method choose it so they have the ability to: (a). Treat the plant side for nutrient deficiencies using hydroponic type nutrients. (b). Treat the plant side with pesticides, fungicides etc that may otherwise harm the fish. (c). Treat the fish side with disease or parasite control products etc... You won't get organic certification running a system that way.

Another of these operations, in South Korea, is less than two years old and is currently turning over in excess of US$1M per month. It runs a very large hybrid system, very successfully, so much so they are currently in the process of doubling the scale of their operation.

De-coupled systems may find their place in the market, but IMO they go against just about everything aquaponics stands for, ie: Growing pesticide free produce and fresh fish, in harmony with nature.

De-coupled systems are primarily promoted by people from aquaculture or hydroponic backgrounds, who IMO haven't been able to change their thinking and can't get their head around the fact aquaponic systems with media beds are eco-systems, containing a broad range of beneficial organisms, such worms, bacteria, fungi, mycorrhizae etc.

I don't think you've really thought this through very well. In defense of the people that are trying this, there is no reason why you can't use organic nutrients in a decoupled system and the same goes for organic pest control. It's just a different way to run a system. There are advantages and disadvantages in going either way but you definitely don't need to decouple your system to run it. The guy that takes a bucket of water from his AP system every week and dumps it on his garden is basically running a decoupled system (the water goes to the plants and never comes back). How would it be any harder to have the system be organic, if you chose to grow organically? A decoupled system with a DWC is much the same except for the water is pumped around within the plant loop.

As far as the people that do this and their background - phhft - some people like to have more control of things and others just like to tinker - probably a whole range of backgrounds and reasons.

If I put down what I thought I would probley be banned from the forum for ever

Since when has that stopped you before Milne?

Personal opinion

If your growing leafy short term crops (and have a decent filter) RAS and leave it coupled.

If your growing fruiting plants have the ability to decouple and adjust (providing you have a decent biofilter)

Best of both worlds coupled RAS (as above) and beds for fruiting that can be decoupled.

There again that does not fit in the mono crop commercial ideal.

Yea I put a post where I sometimes water my wicking beds from the top
and I was chastised for a few people [you cant call them wicking beds ]
So now I just have a heap of dirt boxes
Realy I don't give a rats ;'[;

Dirt boxes! Boxes of dirt to the uneducated Milne.

My boxes sit out in the weather they catch pure rain water, raise the storage level and discard unwanted water into another container for other uses. I haven't watered them since installing them they work wonderfully.
It's just another way of doing things. We always love to read a masters comments Milne.

A Guy I know manages water deliveries from his uncles huge fish farm in Queensland to veggie growers down here in Victoria. The water is nutrient rich fish water delivered by the tanker load, decoupled and isolated just another way of doing things.