Direct flow through system??

[David Nabong]

Earlier in October I had the opportunity to do the tour at Growing Power's facility in Milwaukee. While everything together is very cool, I naturally left with more questions than when I arrived. The big question is what the recirc system they use is most like? Besides the biofilt from the plant beds; which is gravel, supplemented with compost, an primarily monoculture watercress, and strong aeration, the water goes up and comes down.

The raceways work out to 1 fish per gallon(somewhere in the 10000 gallon range), the water is totally opaque and they harvest truckloads of watercress. However the beds don't appear to be ebb and flow, just gravel beds with fill on one side and drain on the other end. I suppose since watercress is an emergent plant, it can handle being wet all the time, but has anyone ever seen, or used this technique? It seems to be somewhat like NFT, but I'm not real sure.

It would seem to be a relatively easy way to go, if you could do more terrestrial type plants, but like I said the AP systems were more or less monoculture.


Thanks,

d

[Sylvia Bernstein]

They added Rich text editing yesterday.  I love it so far, although smiley faces don't seem to work anymore

[TCLynx]

Ok, you are right this is a blog not a discussion.  but did they do a ning upgrade lately or something, some things look different now?

[Sylvia Bernstein]

Not sure what you mean, TC.  They've always been arranged so that the most recent comment on a blog post is shown first, and for a discussion it is the opposite.

[TCLynx]

What's going on, with the site?  The pages seem backwards now?

[Growitright Aquaponics]

Very sad, that is horrible to hear. I feel for those who invest time and energy into a project that ultimately fails. As they say if a you don't succeed....

Hopefully, Feed Denver will be able to rally the support it needs to keep their project going. I wish them the best.

BTW do you know why the back up system failed? I am curious how a brief power outage could cause such a large loss. (I am not asking to be nosey but to learn)  

[Sylvia Bernstein]

As a quick update, I met a board member for one of the two organizations in Denver that I know have built these systems (Feed Denver). They lost every one of the 300 tilapia they were raising in their 300 gallon tank 2 nights ago due to a brief power outage. I continue to be very concerned about these systems and their possible damage to the reputation of aquaponics in the U.S.

[Growitright Aquaponics]

Hi All,
I agree wholeheartedly with David. Growing Power is an amazing place. The approach to aquaponics they take is very different, than what many of us in the aquaponics industry are accustomed to. Aquaponics however is a part of a much larger picture. Their current model is not something for the average AP backyard farmer. That however is not the focus of their non-profit. Their focus is building community relationships and involving all people (some paid, some volunteers and some are even fulfilling community service requirements) including the cities of Milwaukee, Detroit, Chicago and more. Personally, When I think of Will Allen (who I did have the pleasure of meeting at the GP 2010 Sept. Conference) I think of a man with a vision. A person who strives to make healthy living and farming interactive, fun and accessible to all. I can't say I see him as the face of aquaponics but definitely of The Urban Gardening Movement . Big things are happening; I cant wait to see what GP unveils next!

[David Nabong]

@TC- they are using blowers and 12" air diffusers, but not oxygen injection,several of them per raceway. The strong aeration also helped keep solids in suspension. They have a sump pump at one end going up to plant beds, and an open stand pipe at the other end going down into the raceway.
The gravel beds are serving as mechanical filtration, and the flush down the beds and recycle the solid waste back to the compost piles. Water regeneration is coming from rainwater cisterns for the most part if I remember correctly.
Like I said they have a lot going for them: great community support, sweet location from marketing standpoint, tons of donated inputs, high profile marketing, and hundreds of very well intention, earnest volunteers per year.

If we could all have going what he does on that 2-3 acre spot, nobody would be hungry. And I agree, the cress as a marketable product would be a great flow through, but not if your goal is to create food diversity.

[TCLynx]

I think a shallow flow through cress bed sounds like a nice small add on for a system but I probably wouldn't base an entire system on that and watering dirt plants with the water (which uses up lots of water so is essentially like doing water changes as they have to top up to replace that use water.)

Anyway, it is just one more possible method and model.

Does anyone know do they remove solids? (perhaps to feed to their worm bins) And do they have any additional bio-filters? Are they injecting Oxygen to handle such crowded fish tanks?

[David Nabong]

Sorry friends I had to get some sleep, but it seems that the general consensus is that GP is without a doubt an AP model, however much more intensive, in terms of production and input, than what we are all looking at. So while it looks easy, it is not the norm of what each of us is going after. Mr Allen has so many great things going for him at his Milwaukee HQ, not least of which is his back story. What it would appear though is that GP's model is too unwieldy for the average backyard AP gardener.

Thanks for the input, I certainly did not intend to start such a heated debate!