Comment by mastazi | Hacker News Reader

Comment by mastazi | Hacker News Reader

I have been in the aquarium hobby in the past, so when I started looking into hydroponics, for me the natural outcome was to also look into aquaponics[1].

What I like the most about aquaponics (and recirculating hydroponics) is the sustainability aspects, it is an almost completely closed-loop system, with relatively small external inputs compared to other farming methods, and extremely small water requirements (due to the fact that water is continuously recycled).

Two bits of info about aquaponics that not many people know:

1. it is possible to have aquaponics systems in a vegetarian context: in many cases the fish is not for human consumption as food (in large commercial systems this is usually koi that is sold as ornamental fish[2a], in smaller systems goldfish kept as pets[2b]).

2. there are aquaponics systems that don't require access to electricity, in particular the iAVS system (a.k.a "sandponics") was developed with subsistence farmers that had no electricity access in mind, it doesn't require water to be pumped continuously, rather you are only required to manually recirculate the water a few times a day which can be achieved with a bucket or other low tech solutions[3].

[1] https://en.wikipedia.org/wiki/Aquaponics

[2a] https://www.pvrkoicentre.com/pages/aquaponics

[2b] https://farmingaquaponics.com/caring-for-goldfish-in-aquapon...

[3] https://garydonaldson.net/home/iavs/

If you want inspiration to build a bit larger aquaponics system, then maybe our build can help. We have a system with place for about 7000 plants, with two fish tanks of 4.5 m3 each. We have about 200 rainbow trout. Total system water volume is 38 m3.

We are also running a prototype setup where we take roots and plants not sold and feeding them to mealworms, which will become food supplement for the fish. This way we won’t need to feed them as much conventional fish feed.

This is a pilot and demo facility, and we have spent about 15 000 hours building it and learning, and material cost has been about €200k.

http://cirkularodling.se/build-an-aquaponic-indoor-farm-part...

Visited your website but I don’t speak that language so I couldn’t understand it, but looks like you use a method similar Nelson and Pade…? One thing we did to increase rev per area of space was inoculate wood with mycelium and hang it above the water. You could harvest market desirable mushrooms along with your produce and protein. Also, incorporating shrimp to further add to the process of breaking down the ammonia particulates during the transformation to nitrate can be beneficial and another rev stream. Are y’all profitable and scalable with the ops you’re running?

I’m kind of bummed because I was hoping there were going to be a lot more people focused on this and scaling it, but in this thread there are not…

The build log I linked to is in English. We will also publish more in that if you want to follow it.

This is a pilot facility, but looks similar to what Nelson and Pade offers at a quick glance. The commercial scale facility will be very different than this. The scale is 50-100 times larger and you can think of the growing area of this as one layer in a multi-layer facility.

This small scale pilot is far from profitable. Generally we think you need to be at up to 1000 m2 growing area if you have a facility which is a side business and you take care of it alongside your farm. If it is a business by itself with external distribution you probably need it to be about 10 000 m2. (Of course this depends heavily on your local conditions, what you can sell, at what price etc.)

We are focused on scaling, but that is another story than a demo and pilot plant. :)

Well done! IMHO producing the feed on site is the ultimate sustainability move because it makes aquaponics truly autonomous. In the past I tried soldier fly larvae but I wasn't able to produce enough to sustain my fish, it was just a supplement for them.

Excellent! Both your website and the original post. I think farming in Scandinavia needs a reboot, specially because of unfavour Clima. At the moment it relies heavily on buying food from other countries with better clima and cheaper labour. Unortunately this involves a lot of transportation/contamination. This kind of project seems to point the right direction. For more «normal» people I believe is important to try growing things outside when possible or inside. Then you really understand the real value of what we take for granted on the grocery store.

I set-up an aquaponic system on my front porch a few years ago. My wife was skeptical but I grew some of the finest basil around. Just used a tote filled with goldfish, some PVC piping, and a pump. Unfortunately one evening the raccoons figured out how to pop the lid off the tote - it was a massacre!

Oh no! I had goldfish as pets I can imagine that must have been sad. At least they died for "natural" causes.

It was! They were my urban farming buds. I took care of the PVC, they took care of the pooping, the basil took care of clearing the nitrites out of the water. It was all golden until that masked bandit struck. Now I live out of town - I'm quite sure the bears would eat the whole kit if I set it up again.

A small electric fence can be set up to keep out bears. Fairly inexpensive in the face of food cost savings.

I had a small one in my backyard for a few years. My goldfish would ofen simply disappear. One day they were there, the next day they weren't. They also died often and there were a few causes.

* a good number jumped out as the water level was close to the top of the tank when the water was cycled. Of these, some were found me and others by something else. * birds found and ate them. I was completely okay with this. I never actually confirmed this but it seemed the only plausible reason * illness. The goldfish I bought were feeder fish meant for turtles and were never meant to survive long. Disease was a big component. I would replenish often, but on two occasions within a week or two, all would be dead, old and new. * temperature. We had a deeper freeze than typical for my area in the 20s F. It froze in the pipes and much of the tank. And in the summer we had over 100F

I would have cared more were they fish for consumption. When you can buy goldfish for 10 cents a piece it was too easy to simply replenish than to fix the problems. A more humane, and likely cheaper solution would have been to put a small amount of ammonium chloride in the water regularly. I had a giant bag from setting up the system.

I got a ton of lettuce and tomatoes from the system though and learned a ton.

Hmm... I built a pond last summer as a pandemic project, and just got koi in it a couple months ago. I haven't really thought seriously about aquaponics, but I seem to have most of what I would need right there already if I wanted to start growing something. (Maybe lettuce?)

Right now, the pond has a lot of regular pond plants, including azolla (aka mosquito fern or fairy moss) which about every week or two I cull about a bucket's worth and feed to the roommates's chickens so it doesn't take over the whole surface.

Yes, aquariums, aquatic plants, fishes, hydroponics, computers hobby goes hand in hand. :)

What do the fish eat?

Reply on news.ycombinator.com