After Christmas, but before New Year, this writer went to Baguio and Benguet to visit backyard systems and bigger farms. One such farm is Highland Aquaponics located in Benguet. They have two greenhouses now, both of which are fully operational.
I met up with Jonathon near a Petron station, about 10 minutes away from their farm. He was kind enough to accommodate my request for an interview. He told me that he and his wife lived in the United States for a time but decided to move back to the Philippines. Along with other friends, they built the farm on a parcel of land owned by the family of his wife. Their company also teaches local farmers new farming technologies.
Their aquaponics farm was inside a greenhouse. The frame was made up of painted (to stall wear and tear) metal pipes that are at least an inch thick. Interestingly, the joints were not welded together but, instead, attached via screws. This allows them to disassemble (and reassemble) the structure with ease. As for structural integrity, Jonathan informed this writer that they have survived a couple of storms already.
The roof did not have vents to let the hot air out and to pull cold air in from the sides of the structure. And it was evident because, despite being in Benguet, it was quite warm inside. Jonathan was candid enough to say that everything was a work in progress, that they were learning more with every new farm they build.
The greenhouse also had a rain water collection system. The water that landed on the roof (made of UV plastic), slid down towards rain gutters. They painted the gutters to prevent erosion of metal into the collected water which will likely be bad for the fish. It was also mentioned that their experience with using wood for their first greenhouse was instructive. Avoid wood, even if treated, as it quickly weakens in a very humid environment. This writer couldn’t agree more since, for my backyard system, I had to throw away grow beds made out of treated marine plywood due to degradation.
The aquaponics setup is similar to the University of the Virgin Islands system, the benchmark of the industry. The water is pumped from the sump tank to fish tanks. The water then overflows through the Solids Lift Outlet which pulls the water (along with the fish wastes) from the bottom of the tank and is brought it to the next stage: filters.
The first one is a sedimentation unit (called clarifier, radial flow filter, etc.). Basically it uses flow dynamics and retention time of water to let the bigger solids settle at the bottom while the cleaner water passes through. The next stage is a set of two drum filters, both of which have screens and nets inside to capture the finer solids. And then the water returns to the sump tank.
From the sump tank, there is a second pump which brings the water to the Deep Water Culture (DWC) component of the system. These are rectangular grow beds that are around one foot deep with (aerated) nutrient rich water that come from the sump. Rafts made of polystyrene boards, 2 inches thick, float on the DWC. These rafts have holes drilled through them, and net pots with crops inside slipped through the holes, floating on the water. The water then travels back to the sump tank. The cycle is repeated.
Like the UVI system, there is no separate biofilter or an external re-mineralization tank. And this allows for simple management of the system. One simply has to check the pumps, the aerators, and the pipes in the morning. Then it’s time to feed the fish, check the pH, and add buffers if necessary. The filters are also cleaned, but not daily. Perhaps the time-consuming part would be the preparation of the seedlings.
The entire operation is run by only one full time employee. Extra help comes during harvest time.