Wednesday, August 7, 2013

Aquaponics Update

We now have had the aquaponics systems operational for a year. The first year we had a tremendous lettuce and tomato harvest. There were some challenges with the tomatoes but we feel that all of this is a learning process. First we have to learn and then understand how an aquaponics system operates. Aquaponics is a blend of hydroponics, the growing of vegetables in water, and aquaculture, the farming of fish. One of the key elements is keeping the system in balance so that the hydraulic system is balanced and works, that is, the bell siphons do their jobs as advertised. We believe we have mastered this. There is also the balance of nutrients from the fish and the cleaning ability of the plants. If the ratio of fish to plants is wrong the result is possibility of too much ammonia, nitrates and nitrites in the water. Too much of any of these is detrimental to the fish. On the other hand, there needs to be sufficient nutrients in the water to feed the plants. So far testing has manifested zero ammonia, nitrates and nitrites and a well balanced pH level. Another challenge we are facing is which plants grow best and when is the best growing season for a particular plant. This last challenge is an ongoing process and something that is learned by each growing season.

Our first lettuce crop was bountiful to the point that the boys were tired of eating lettuce. We in fact were able to sell some to another local orphanage. So it was a win/win situation. Unfortunately our second and third lettuce crops were wiped out thanks to the birds. We were surprised how they managed to clean off large lettuce plants in no time at all. In fact, they wiped out an entire lettuce crop in a matter of three days. So  not only were we faced with balancing the operation of the system but now we had to counter the birds harvesting the crops before we had a chance to. The plan now is to envelope the entire system with shade material. The photo below is the beginning of this construction phase. To save cost, all of the material for the walls are being sewn by Nancy, a formidable job with the largest piece being over 24m (72 ft) long – the long wall shown in the photo. We have also purchased a tool to put in the grommets. Interestingly enough it is difficult to find grommets in the local area – just another challenge in the long process. (Although we can find people who will put in the grommets, they won't sell them to us)


On the positive side we had our first fish feast last week. The boys managed to catch a large number of fish. However, only those greater than 300 grams were kept. We ended up with 20 fish amounting to approximately 7 kg or roughly 15 pounds. The comment back was that the fish were very tasty. However, again there is a challenge here. The fish of choice is tilapia since they grow the fastest and are a favored fish in the area. The challenge is that the water is 22C and should be 27C for maximum growth rate and size. So now an approach to heating the water needs to be developed and implemented. We have a concept in mind and now need the funds to accomplish this task. This photo is of our “fishermen” and their catch. Go here to see them catching the fish.


The biggest challenge we face, and one that tremendously impacts completion of the total system, is sufficient funding. We use volunteer labor whenever we can but materials and various special purpose elements, like the metal structure, require money. We are slowly but surely getting to a complete system that we feel is fully functional and producing the desired results. There is always an opportunity for anyone willing to contribute time or funds or both whenever they can!

No comments: