Why aquaponics?

Compared to traditional farming, hydroponics has the potential to produce food while being much more efficient. Most hydroponics use a soil-less medium, eliminating the need for crop rotation, irrigation, or any of the other complications that come with soil. Hydroponic gardening also uses around 85%-90% less water than a normal garden, water that would normally be lost through runoff is instead recycled through the system.

There are a few obstacles to hydroponics, to be commercially profitable you need a lot of equipment and space. In the spirit of being a controlled system most operations are also indoors, safe from harsh weather or other pests. Also with no soil you have to supplement nutrients manually, at least from a hobbyist's perspective this can become quite costly. Aquaponics is taking all of the same principles from hydroponics, except adding fish into the equation to solve the fertilization problem.

The cycle starts with the fish producing ammonia, nitrification bacteria convert ammonia into nitrate, plants remove the nitrate from the water and it cycles back to the fish to start all over again. Cutting the costs and time spent from adding nutrients to your water is the largest benefit over hydroponics in my case. In a perfect aquaponic system the only input required would be food for the fish. Compared to fertilizer the food is cheap, and automatic fish feeders aren't anything new. In larger operations the fish themselves are another product, with separate tanks for spawning you could potentially maintain a healthy population of fish.

It makes sense to take an existing system found in nature and try to sustain it in a controllable environment, rather than trying to manipulate the system in an uncontrollable environment (irrigation, pesticides, artificial fertilization etc) which could have negative consequences. My project is an attempt to do exactly this, I may not make enough food to feed myself but it's a learning experience nonetheless. My ultimate goal is to learn the ins and outs of aquaponics and educate / offer services for anyone else who would be interested. As I go along I hope to come up with a well documented design that anyone could follow if they wanted to try it for themselves, or in other words, I'm making a lot of mistakes so you won't have to! I'm also hoping to use as much automation as possible along with a bunch of sensors and other fun things, I'll post information on these as well if I can get them running.

I've got an optimistic and cheesy vision for the future and can see this supplementing the future of produce, less big agriculture and more local DIY produce. The benefits are too great to ignore, no need for pesticides, no fertilization runoff, efficient use of water, and being able to produce in any climate year-round reduces the need for transporting food (saves money and lowers carbon footprint). It can be taken so much further too, apply solar energy for any electrical needs, spawn your own fish, keep bees for pollination, and maintain a mealworm colony for fish feed (feed them compost) and you've got a nearly perfect loop!

Thanks for checking it out!

BUILD DETAILS

MODULAR: The wooden frame is built and designed to be expanded if desired. By using bolts instead of screws I can disassemble it and easily add to the length of the frame. Initially I had purchased enough wood to make it 8' long rather than 4', but due to space issues I had to settle with 4'. Now that I've moved and have more room to work with I'm planning on cutting more material to increase the size.

AQUARIUM: The tank is 55 gallons and I picked it up for $25 at a local thrift store, which is an incredible deal considering I've seen new ones go for around $150! The currently stocked fish are 5 bluegill and 1 bullhead. I do not yet know if I've reached the most effective levels of ammonia for the nitrification process with the amount of fish I have, but I plan on monitoring this in the future. I've got a pump that feeds up to the trays via a manifold that splits it into three ways, it's capable of moving around 900 gallons per minute which is way more than I need so I have it restrained by using quarter-inch vinyl tubing (may downgrade eventually). The pump runs twice a day, for around an hour each time, and fills the trays using the ebb-and-flow method. It's almost a bastardization of ebb-and-flow and NFT since the channels are so shallow (due to the drain being low in the tray) but seems to be working just fine. There are two airstones for dissolving oxygen being fed from the same air pump, it wouldn't be a bad idea to buy a separate air pump for redundancy. And finally, I have a tank heater that keeps the temperature at 72 degrees. This is quite warm for the types of fish I'm using but if the water becomes too brackish they won't eat as much and that awesome nitrification-fertilization process may slow down. For fish feed I primarily use dried mealworms, I tried to start a mealworm colony but couldn't get that ecosystem running. Being able to raise my own fish food that would subside mostly on compost would be awesome though, I'll have to try it again in the future.

TRAYS: There are 3 trays which are about 4.5" x 6'. Each tray is lined with a food-safe HDPE pond liner and prevents the water from rotting the wood away. The trays sit freely and can be moved as needed, one side is sanded slightly to make a 1-2 degree incline so that the water will pool on the end with the drains. Another benefit of having three separate trays rather than one large grow bed is that I can experiment with different growing methods. For example, I may isolate one tray and use artificial fertilization to see the difference in growth between that and the aquaponic element.

POTS and GROW MEDIA: The trays can fit 30 4.5"x4.5" pots, despite this the plants may require more room apart from each other so I doubt I'll ever run it at this capacity (unless I'm only growing lettuce). Like the trays, the pots are not attached to anything and can be moved around if necessary. This has been really handy as I've had to do a lot of rearranging for several reasons. I was concerned that by moving the plant it would get stressed and die, but I guess I was just being paranoid since doing this doesn't seem to have any effect on plant health as long as I'm careful. I'm using GrowStone as the media to support the plants, I prefer this over hydroton since it's larger in volume, much less dense, and easier to work with (sick of dropping hydroton pellets and chasing after them). I haven't used Rockwool and hear that it works quite well, but it's really expensive and is only meant to be used once. Nutrient film technique is something I'm really interested in and requires no media at all, that's really sexy from a cost perspective and all I would need is something to act as a plant support. The process I use to start a plant goes as follows: I use tree bark plugs and a germination tray to start the seedling. Once it sprouts and the roots are visible from the bottom I fill one of my pots with GrowStone and transplant it from the tray into the pot. The water runs fairly shallow in two of my three trays so I just need to make sure that the roots will be able to reach down to the water. It's also important to have a good amount of top soil, or a top layer of GrowStone in my case. If the surface gets wet and is exposed to light then algae becomes a pretty annoying thing to deal with.

LIGHTS: I have two ballasts using T5 florescent lights, each ballast has 4 4' long bulbs. The lights are on a 18/6 timer, that is 16 on and 6 off. For plant growth it would be optimal to do something more aggressive such as 22/2, but since the fish are affected by the light I wanted to establish a more natural cycle so that they wouldn't get stressed. It would be interesting to put together some blue and red diffused LEDs to play around with, the T5s aren't that expensive to run but the bulbs do need to be replaced at least once a year for optimum growth. Currently I'm running without lights since my setup is getting plenty of sunlight, though they would be a good supplement during the winter months.