Technology Aquaponics Discussion

[Bear Ribs]

I've been looking a bit at Aquaponic systems for growing food lately. Seems like a pretty good system for growing quite a bit in a small space. Typical garden vegetables mostly grow well, with nightshades (including potatoes) and lettuce being particularly good, though larger plants with extensive root systems like asparagus seem to have problems. Obviously, trees are right out.

I've been looking at chop-and-flip aquaponic rigs myself for the future. Pricing things out, you can get a half way decent rig for around 300-1000 USD. The downside is you need both to be able to test your water and to have a working pump.

The biggest negative I can see is the need for frequent water tests and a pumping system that can fail. With the current climate of supply chains disrupted and goods potentially being scarce I'm not eager to be dependent on an electronic part I might not be able to get in a pinch. I'm looking at wind-powered pumping options right now to have a backup system but haven't come up with a satisfactory design. The other issue is temperature as you have to carefully match your fish to the temperature of the water, at too low a temperature, f'rex, tilapia will quit eating and thus quit supplying nutrients to the plants. This can be solved with a water heater but spending more on electricity isn't the gameplan.

The upside is that it supplies fish along with vegetables which is quite nice for a home garden system. It also grows faster than soil does.



Does anybody have any experience with these grow methods?

 

[Bear Ribs]

Having done a lot of research on this over the past few months and crunching the numbers repeatedly, I'm going forward with my design. A local farm supplier sells 9' round stock tanks for 450 dollars each, which contain about a thousand gallons of water. I plan on refitting a number of plastic Rubbermaid totes into media planter beds, altogether with pumps, expanded clay media, plumbing and wooden structure, 55-gallon drums for filtration, sump, and a settling tank, plants, and fish I'm looking at around 1600 to get started today. As a chop-and-flip runs around 900 currently for a measly 250 gallons, this is the way to go. I intend to build a greenhouse around it to extend the growing season around October. I intend to build large enough to add a second tank next year.

Coppernose Bluegill can live comfortably at 1 pound of fish per three gallons and while they do get up to 12" and 2 pounds, those are quite rare and I wouldn't want to waste the food adding those last few ounces, I intend to harvest them at around 1/2 pound. I intend to add channel catfish fingerlings since they can live with bluegill and will eat food the bluegill miss (and leftovers) as well as giving me some variety. I can reasonably expect, with some losses, for this system to supply around 1-150 pounds of (processed) fish per year which is going to be a huge help if a food crunch hits, basically one fish dinner a week for three people and maybe a couple of fish sandwiches a week if things go well. Fingerlings are available at 50 dollars per 100 fish.

Tilapia grow faster and produce more meat than bluegill but also die at 50 degrees, which is early fall weather here so I'd need to build a greenhouse sooner and employ an expensive water heater on the tank. Tilapia also breed in captivity well so they're worth looking into next year when I have a greenhouse to see if I can keep it warm year 'round (probably not, it gets into the negative teens here).

Plants are extremely varied in what you can grow. Leafy Greens are best to start so I'm going to focus on chard, bok choy, kale, spinach, and lettuce with a few tomato plants and expand as the fish grow. I'm looking into spice plants, leafy herbs like Rosemary, thyme, parsley, and mint seem to do well though mint is very aggressive and has to be harvested at a rapid clip to keep it from taking over the bed. It will take some time for the fish to grow large enough to support a full-plant bed so plants have to be added weekly. This isn't a huge problem since I also don't want to eat 500 pounds of lettuce in one week so harvesting weekly is also better.

Apparently, raspberry plants do very well in aquaponic systems but cannot be planted in the same bed as any nightshade so I plan to hold off on them this year.

 

[Rocinante]

I've set up a rdwc hydroponic system before (recirculating deep water culture) with some shit from home Depot and an aquarium water pump.

It was enough to run four buckets with one large plant each.

I had the room lined with Mylar, I ran metal halide lights for the beginning phase of the plant's life, and high pressure sodium lighting for the end phases (more red spectrum) or maybe it was the reverse. I can't remember now. But one has a more blue light (MH) and one had a more red light. If I am remembering right a red light encourages more flower growth while blue encouraged more vegative growth, so you finish off with a more red spectrum during the plant's flowering stage.

I also had a slow release co2 system and some nice air circulation with an exhaust using carbon filters so the neighbors don't get overwhelmed by the smells of my indoor garden. I started off actually brewing with sugar and yeast and covering that container with a balloon with a small hole in it, but eventually moved on to having a CO2 tank slowly releasing.

Then had to control humidity.

pH with the water is a big deal. There's testers and products you can buy that will raise and lower it. And nutrient balance can be a little complicated. But back then you could get starter kits that come with all the nutrients you need and instructions written for how much to use in each cycle. Then just buy more of what's needed when you need it. Made things nice and simple.

Clay pebbles work good to grow the plant in. You wouldn't want to use soil in this kind of setup. What actually happens is you pump the water through some lines and drip it on top of the clay pebbles, which rest in a basket mounted to the bucket. it then drops into the bottom of the bucket, and at that point gravity and pressures comes in to play, you'll have some more tubes in the bottom of the bucket that drains the water back to your main reservoir. It's then continuously circulating, and you just add more nutrient filled water as needed.

Once I got timing and plant cycles down, I was able to get a good rhythm going, and I had one small closet for seedlings, one room for plants in vegative stage and one room for plants in flowering stage. This worked great because they each have different lighting/light cycle needs. Much more efficient than using one room for the whole process. You can produce a lot more.. "tomatoes" this way.

Man...I grew the best "tomatoes" in town. It was fun.

I got out of the tomato growing game when my best friend and tomato growing business partner betrayed and robbed me.

 

[Bear Ribs]

I have my aquaponic rig up and running now. Supply-chain snarls made it take almost two months late, bulkhead valves are ludicrously hard to find for some reason.

The Stock tanks never materialized so I picked up three IBC totes for fishwater and some 33 gallon drums I've sliced in half for planter beds. I'm using split-flow because my pump is about three times more powerful than I need for this setup, as I plan to expand once this initial proof-of-concept is up and running.

I don't expect to get many vegetables out of it this year due to how long it took to make but I'm going to throw some swiss chard, lettuce, and kale in, all fast-growing varieties with less than two months of grow time since I anticipate bad weather by october.

Phase 2 is throwing up a greenhouse around it, which I will try to do in October if all goes well.