This multi-faceted project is a culmination of years of planning and resource aggregation. The chief financial backer has consistently been the New York Restoration Project (NYRP) which owns Imani I. NYRP donated the two ponds and paid for the solar panel, storage batteries, AC inverter and wood in the storage shed and arbor included in this project. The essential components of the project are:
As you can see, virtually all of the materials not donated by NYRP were salvaged or repurposed. This is consistent with the mission of the Imani’s and Green Phoenix Permaculture, the organization co-sponsoring the Imani Gardens, along with NYRP, to demonstrate permaculture principles.
But what is “aquaponics”? According to Wikipedia, aquaponics is a sustainable food production system that combines a traditional aquaculture (raising aquatic animals such as snails, fish, crayfish or prawns in tanks) with hydroponics (cultivating plants in water) in a symbiotic environment. Accordingly we have introduced both fish and plants into our pond system to create the symbiotic environment defined as aquaponics. At present this system is in a trial mode while we balance the inputs and outputs to make sure everything runs smoothly. The fish in the pond are 25 small goldfish bought from a local pet store (for $3!) and the plants are about a half dozen mint and sage plants placed in boxes in the urbanite waterfall. So far, the fish have thrived and eliminated a lot of mosquito larvae that were living in the pond.
The plant and fish systems are connected by pumping water from the pond to the top of the waterfall. To pump the water, we have installed a 500 gallon per hour submersible pond pump powered by the solar panel.
One of the first things we discovered when we began running the system is that the solar panel provides only enough electricity to power the pump for about 10 minutes every 24 hours. While this has proven adequate to keep our small fish population happy, we expect that raising larger fish such as tilapia or catfish will require more pumping. Accordingly, we expect to have to install at least one more and probably two more solar panels.
How do the plants and the fish help each other? Again from Wikipedia “Nitrification, the aerobic conversion of ammonia into nitrates, is one of the most important functions in an aquaponics system as it reduces the toxicity of the water for fish, and allows the resulting nitrate compounds to be removed by the plants for nourishment.” In other words, the fish poop nitrogen which becomes plant food when it is circulated through the waterfall by the solar powered pump.
Consistent with permaculture principles, this system requires no external inputs except sunlight. As long as the sun shines, this system, once properly balanced, will be completely self-sustaining.
Our hope is that with more solar power and more plants, we can introduce larger fish into our pond. Time will tell. In any case, this project is an exciting one and one incorporating a number of permaculture principles. Who knows, maybe next year we can serve tilapia and catfish with the lobster at our annual fall fundraiser!