Saturday, December 20, 2008
Philippines Aquaponics: Self-Sustaining Agriculture and Aquaculture
Believe it or not...I did this on accident.
Labor Day 2008: I have nothing to do on my vacation. I'm 10,000 miles away from the United States, sitting idle on an island, one out of the 7,100 islands in the Philippines. As I went through my normal selfish list of what to do on Labor Day, I thought to myself, maybe I would do something different this year?
Then I realized...the house I'm renting has an empty unused pond with a small idol of Mary. Maybe I could put fish in the pond and my baby girl could enjoy watching it? (My advice to Catholic friends: Mary was a respectable woman, but don't worship humans, especially human idols. Please read the Ten Commandments in Exodus 20: "You shall not make for yourself an idol in the form of anything in heaven above or on the earth beneath or in the waters below. You shall not bow down to them or worship them." You now have been taught the correct doctrine. You are now accountable to it.)
Summary 1: Laziness Breeds Ideas
As I thought of what type of fish I could put in the pond, I then remembered my teenage years when I owned an aquarium. It was a disaster. My laziness killed my pet goldfish in the past. I didn't change the water and they all died. Why in the world would I try that again? I certainly don't want to change the water in a 300 liter pond (400 liters with other additions)! But I still want my baby girl to see fish swimming about. Hmmm.... How to grow fish without doing much maintenance work...
Summary 2: Looking at Nature/Science
I started researching what type of filter could automatically remove fish waste (ammonia/nitrite/nitrate) from my pond without me having to change the water. Alas, there was none! A water exchange was still necessary with most mechanical filters. Then I turned to biological filters ... this is when I found aquaponics, the combination of fish farming (aquaculture) and growing plants without soil (hydroponics).
In nature, we see it all the time in swamps and ponds. Plants that grow near the water or on the water absorb the nutrients from the fish waste and help clean the water.
Fish can even survive in closed loop environments because of this natural occurrence. For example, bass in many of Florida's lakes and ponds which have no natural springs.
Summary 3: The Build
When I mentioned to my family I was going to start a project that would grow fish (tilapia) that could be harvested plus it would grow plants that required no soil -- they thought I was crazy. But I wanted to create a project that would be productive, something cool for my baby girl to play with, and at the same time, help reduce the cost of food.
I initially bought two aquarium pumps, one aerator, two hoses, and some plastic bins as a growth bed. I planted Chinese upland kang kong and they grew fine. I then upgraded it to a bigger growth bed and even added two rain gutters to test out the nutrient film technique (NFT). Hydroponic growers use NFT systems and introduce small trace elements of nutrients to grow their plants -- I'm doing the same thing except my nutrients come directly from fish and they clean the water for the fish to continue to live and reproduce.
Summary 4: No Fish Kill w/ Zero Exchange in Water!
I have so far introduced 160 fish and the only kills I got were during the transfer process. My tilapia fish that died was due to the rapid change in temperature, but once they were in the pond and initially lived through the shock of being taken away from their previous environments, they lived and grew big! No fish kills post-transfer and I didn't do any exchange of water. The plants reduced the fish waste by themselves without me having to exchange the water! The only water added are the ones lost in evaporation (estimate about 10% of the volume a month).
Summary 5: The Bacteria Cycle Took About Two Weeks
There's a natural cycle when bacteria starts growing and it starts breaking down the waste products of the fish into usable trace elements that the plants could eat. It took roughly about two weeks. Thankfully, tilapia are tough fish and they survived fine through this cycle.
Summary 6: The Plants Bear Fruit Early and Grow Fast
I planted two sets of upland kangkung plants, one on the ground and one on the growth bed. The ones on the growth were 2x-3x taller than the ones on the ground, suggesting this little experiment might actually work. (Why couldn't I think of this during high school, I would have won so many science fair awards?)
Summary 7: What This Experiment Means For Farmers
This is doable commercially. Imagine growing crops on an entire field without chemical fertilizers, growing without being infected by soil based diseases, and at the same time, you have a fish farm that requires no additional water and it doesn't pollute the water in your area. It is a self sustaining system. You can also introduce solar pumps and solar aeration, something I did recently to reduce my dependency on electricity.
Plus it's a cool thing to show to my 2 year old daughter -- she feeds the fish with plants from the growth beds every day.