Siphons are the most pervasive methods of emptying the water from a media bed. Generally, a siphon works by establishing a pressure difference between the water-filled section of the media bed and the end of the siphon tube leading into the reservoir or fish tank. To work properly a siphon must first "engage" which means to fully establish this low pressure vacuum that will suck the water out. A common example of this is to use a tube that's submerged in water so that no air bubbles exist. If you were to take one end of the tube and lower it so that it is lower than the end that serves as the water intake, the water would naturally siphon out, naturally getting pulled by the collective pull of low pressure similar to what happens when you drink through a straw.
There are many configurations of piping that can do this but in my experience the bell siphon is the most popular. Bell siphons have some good benefits. They pull from the bottom of a media bed, ensuring that most of the water is expunged but also they tend to concentrate bottom sludge into one point and get clogged. Bell siphons are great if your input flow rate is very small as you can reduce the bell siphon standpipe quite significantly to work in low flow rates (more than 20 minutes to fill media bed). They're fairly easy to engage with proper diameter-reducing funnels to decrease the amount of water required to fill up the downstem and thus start the pressure differential. They're fairly easy to make. But what if I told you that there's something that's easier.
U-Siphons, as you can now tell, are my favorite way of siphoning media beds. They're much more simple to make, incredibly easy to install and tune, and engage consistently as long as the pump input is less than the siphon output when it still has not quite engaged. U-siphons are also completely external from the media bed so they do not take up valuable growspace and they're very easy to modify and troubleshoot as there is no excavation required if it were to get clogged or needed to be removed for maintenance. Additionally, you have the options of placing it on the side of the bed with a slitted intake pipe that extends the length of the media bed and takes in water from many points, not just one as the bell siphon does.
All in all, each application has it's appropriate solution but next time you find yourself looking for a way to empty your grow beds, consider a U-Siphon.
There's not a lot of information about aquaponics out there and I've noticed that in order to gain a lot of attention, the information shelled out can be over exaggerated or embellished. Before I talk about what aquaponics ISN'T I'd like to say first what it IS.
Aquaponics is, at its core, an agricultural method. This method isn't an exemption pass to all the forethought of garden design. It does however mitigate a large percentage of labor and resources involved in agriculture. It uses far less water, requires much less additions of nutrients, allows you to virtually ignore soil related work and problems all while growing the plants at higher densities and grow rates. Nature constantly reminds us that there is no free lunch; everything has a price. This is certainly true with aquaponics as you are responsible for the wellbeing and growth of fish. Fortunately for the farmer, fish aren't exceptionally hard to take care of as long as you keep their tank and water comfortably clean so the tradeoff between the benefits and additional work isn't a tough call to make for many.
What aquaponics ISN'T is a fool-proof, so-easy-your-dog-can-do-it technology that basically grows your vegetables and fruit for you. While a well kept and properly established aquaponic system can certainly give that illusion, the road to that goal is one of learning, adapting, and most importantly observation. You still have to use integrated pest management; that is to say think about your systems surroundings and consider temperature, light, humidity, and other factors that may affect your fish or plants. Include plants that attract beneficial insects and group together synergistic plants like legumes and veggies of many varieties to lessen the chance that one disease decimates your entire garden. These caveats may be off putting to those who want the benefits of a garden without the work, but the labour itself can have you reap other rewards. It teaches observation and the effectiveness of giving direction your efforts. It teaches patience and commitment to a goal that may take months to achieve (especially in the case of fruits). It teaches you the incredibly invaluable lesson of how to fail. While I by no means wish to dishearten, as a small aquaponic system can realistically be maintained with a maximum of 20 minutes a day, there will be moments of failure that are opportunities to grow and instrumental to learning.
The most important and final caution I want to impart is that aquaponics is extremely addictive! Once you start making progress and see how powerful your effort can be, you'll never want to stop. So, for those wanting to give aquaponics a shot I say to you: there is no time like the present. If you encounter problems or need guidance we'd be happy to be a helpful friend along the way.
Cheers and Good Growing
Looking at the trend of trends, I think it is only now in this recent decade that environmentalism and sustainability have been brought to the forefront of design, both architecturally and for consumer products. Without getting obnoxiously into how I think corporate-funded media tries so hard to convince us that the consumer can solve massive industrial pollution, I do believe that efforts can be made on the home-front that could provide unprecedented levels of healthful food production and incite massive change in the agricultural and logistical behemoth that is the food industry.
What I'm talking about is what I call integrated aquaponics, which is to say aquaponics that is incorporated into structures to foster a natural circular path of energy. Let me paint a picture of an example I have had in my head, but be warned, I find that thinking in terms of numbers give you a more concrete thought so bear with me through the math.
A small insulated room of 7' x 6' located anywhere convenient on floor level (unless you're willing to spend a hefty sum to support at least 5 tons of water weight) can be made to comfortably hold 1000 gallons in a specialized tank about 6 feet in height. With proper aquaculture practices you can hold about 150 tilapia or other types of edible fish, feeding them high quality feed at a dollar per half pound (this translate about 0.60 USD per day for the food of 1000 fish). With this amount of fish it is possible to have around about 150 cubic feet of grow bed. It has been documented (https://portablefarms.com/2019/feed-5-portable-farm/) that it is possible to feed a family of five with 125 cubic feet of growbed. Through thoughtful design this should not be prohibitively expensive due to the fact that an aquaponic system is fairly simple in concept: Water flows from the fish tank to a filter, then to the growbeds. A sump pump that can fill all 1000 gallons of growbed 4 times to 8 times an hour will cost $200 dollars at most and all electricity used by the pump and filtration system can more than compensated for with a 1 kwh solar or wind system. Solar is expensive but assuming that 15 watts can be generated per cubic foot for panels with efficiency ratings of around ~16%, you would only need about 70 cubic feet of solar panels for 140 cubic feet of growbed. While this can be expensive at around 1,000 to 1,500 USD the return of investment happens pretty quickly if you consider the fact that a family of 5 may be spending around 700 USD on groceries every month (https://growingslower.com/how-much-should-you-budget-for-groceries/). It must be said that these numbers and prices I use are in no way in stone. I simply think it helps to form a mental "sketch" that gives me a perspective to see the plausibility and practicality (or lack thereof) of my thoughts.
The bottom line is that aquaponics can definitely be incorporated into the house of the future with solar tubes bringing powerful sunlight onto aesthetic aquaponic growbeds or living walls full of fresh produce ready to eat. The first steps will be difficult, and probably not cost efficient until two or three years of tinkering and getting the system well cycled, inoculated and producing optimally but the goal is revolutionary. This design aims to decentralize where food comes from to lessen the load on massive mono-culture farms on dwindling arable land. Image a neighborhood of these houses. Each house would be a biosphere providing an incredible diversity of food that could be shared and traded with neighbors or sold at a local food market. Additionally, all the solid waste caught in a house's aquaponic filtration system could be easily sent to an outside re-mineralization tank to become wonderful fertilizer for an outside garden.
In addition to a possible 20-30 lbs of fresh fish a month, the system will inherently require good airflow and comfortable humidity in the home. This has the added effect of focusing the design process to the overall comfort and freshness of the environment within a living space. The indoors would have to be bright and sunny during the day and glowing in the moonlight by night removing elements of home that separate us from nature and the cycle of the sun. With a passionate designer, patient and hardworking builders, and skillful architects the possibilities are truly endless.
Cheers and Good Growing,
The Kodaponic blog's purpose is to document how we grow and share the trials and success we encounter along the way. Additionally any interesting aquaponic news and research will be posted here, as well as resources that help us (and hopefully you!). Today I'll start of with resources:
I've been professionally involved in Aquaponics for a little over 3 years and worked in food science research throughout college so I wanted to compile some of my favorite resources that taught me a lot of invaluable tips and techniques. I'm interested in what you all have been reading and eager to learn more! Here are my favorite in no particular order: