Aquaponic Build: The Functioning System
The Aquaponic Setup
With the basics of small aquaponics previously covered, all that's left now is setting up the functioning system. While it might sound a bit dry and boring, this really is the most exciting stage of any aquaponic build. Your creation finally comes to life, and best of all, your first harvest of homegrown produce is right around the corner! But, let's not get ahead of ourselves too much; there's still much to cover. This article will discuss key aspects of the nitrogen cycle, stocking your aquarium, water pump and light usage, as well as planting your first aquaponic seeds. After you're through with this stage, you can truly say that your aquarium works for you!
The Aquaponics Nitrogen Cycle
- Fish wastes, combined with the decomposition of excess food and plant materials release ammonia into the aquarium water.
- Nitrifying bacteria present in an established aquaponic system convert the ammonia into nitrites and then finally into nitrates.
- Growing plants quickly consume the readily available nitrates, thus returning filtered water back into the aquarium.
Stocking the Aquarium
Turns out, this part seems to be the trickiest, especially for beginners. The guidelines for stocking an aquarium seem to be hazy at best, with the one inch of fish per gallon rule proving to be not true. If you really want to maximize the efficiency of your aquaponic system, you'll want to glance at the following criteria:
- Choose fish that are size appropriate for your aquarium! The goal here is not to torture fish, but instead provide them with a happy and healthy living space. The best practice is common sense! The fish for a 10 gallon tank is a two inch minnow, not an eight inch cichlid!
- Stock in stages, adding only a few fish at a time. Introducing larger numbers of fish can quickly overload the established bacterial colonies, leading to excess ammonia in the water. These poor water conditions and lead to fish fatality in a rather short amount of time. To prevent poor water conditions from developing, add a few fish, then wait a week for the bacterial colonies to adjust to the added workload before adding more.
- Slightly overstock the aquarium. The growing plants use a great deal of nitrates and can handle the extra load of a few more size-appropriate occupants. For example, the 10 gallon aquaponic system shown contains three fathead minnows, five white cloud minnows and 10 ghost shrimp. The aquarium occupants all have enough space to swim freely, but also live in great enough numbers to support the hungry roots of growing crops!
Light and Water Pump Usage
Venturing out of the aquarium, we now shift our focus to the veggie grow bed. For healthy crops that continue to thrive, it's essential to pay close attention to photoperiods and water delivery!
- Light Usage - The spectrum of light and the length of the photoperiod (time exposed to light) will be different for each stage of plant growth. Though some species of plants will differ, the table below illustrates general photoperiod lengths and light spectrums for each stage of plant growth.
Spectrum of Light
Heavy 6700°K, with 2700°K
Heavy 2700°K, with 6700°K
- Water Pump Usage - Since plant roots need oxygen when the lights are turned off, the water pump should only be setup to run when the lights are on. Now, when it comes to how long the pump should be run for, it seems to be more of a personal preference. Many people choose to run their pumps for 15 minutes every couple hours. I on the other hand allow my pump to provide a continuous drip the whole time the lights are on. Tinker around a bit with your aquaponic setup and see what works best for you!
Planting Aquaponic Seeds
With your system tinkered to your liking, the first seeds can finally be sown! Again, many gardeners will have their own preferences as to how the seeds are started, but really, there's a bunch correct ways. Personally, I like to plant the seeds in rockwool for germination. This inert grow medium has near perfect water to oxygen ratios, allowing for quick and healthy seed germination.
- Seeds Requiring Light to Germinate - These types of seeds are the easiest to germinate, as they can be placed directly into the grow bed to sprout. During the germination time, the lights can be left on 24 hours a day. The rockwool should also be hand watered so that it is moist, but not soggy. Usage of the water pump may begin once the seeds have sprouted.
- Seeds Requiring Darkness to Germinate - Some seeds will not need any light to germinate. For these types of seeds, place the moist rockwool containing the seeds in a dark and preferably warm place until the seeds have sprouted. Once germinated, transfer immediately to the aquaponic grow bed.
Alright! With the seeds finally planted, your once regular fish tank has now officially been converted into a full on aquaponic setup. That's pretty sweet, if I may say! It's been quite the journey thus far, and with all the hard work now out of the way, all that's left is aquaponic maintenance. Of course, this will be covered in my next article, so I invite you to have a look. As for now, thank you for reading this article on creating the functional aquaponics build! Please feel free to leave any questions or comments that arise!
Curious? I know I would be! After talking all this time, seeing a video example of the 10-gallon aquaponic setup would be pretty cool, right? Well, you're in luck! Below is a recent video of my experimental small aquaponic setup. The plants growing above are now about three weeks from seed. Enjoy!