Tom Mitchell and Mike Griffin walk up and down the rows of their produce. The lettuce and kale are going strong. The tomatoes are a little more touch and go. And near the front of the greenhouse, water softly trickles into a large tank, where the occasional splash can be heard as fish jump.
Water is the keystone of Griffin and Mitchell’s operation, Four Seasons Aquaponics.
You may have heard of aquaculture, which is the process of raising fish for market. Or hydroponics, which is the process of growing crops on water.
Aquaponics is the combination of the two.
“I started thinking about it 15 years ago,” said Griffin in an interview in the partner’s aquaponics greenhouse. “I’ve had fish my whole life. One day, I took a lighting grate and put it on top of the tank, and put in some houseplant cuttings. They grew like crazy.”
In August, Griffin partnered with Mitchell, who had an interest in aquaponics, to start a business with the hopes of selling produce and fish commercially to local restaurants.
The two have spent the last few months experimenting with commercial-level growing in their aquaponics greenhouse. They have the potential to grow about 4,000 plants.
“We have to focus on volume,” said Mitchell, “and balance that with cost. The things that are doing really well are our head lettuces, kale, basil, a lot of our greens. We’re currently experimenting with peas.”
Mitchell and Griffin hope to produce 20-30 pounds of produce for local restaurant orders, and to grow specialty items upon request. One of the advantages of their operation, said the pair, is that they grow year-round and can produce products over the winter and before the traditional growing season.
The general process is simple, said Mitchell. The two raise tilapia, a type of South American fish, in large tanks within their greenhouse. The fish waste is allowed to settle and then treated to remove certain toxins like ammonia, leaving only the nutrients behind. The water, complete with the nutrient rich waste, is sent down long trays where plants float on rafts, their roots hanging through holes into the water, where they get their nutrients and grow. The unused water is sent back to the fish tank and the process begins again.
While the businesses biggest expense is heating the water for the fish tank, since tilapia are warm-water fish, they can save in other areas – particularly in the fact that because most of the water cycles through the system and is reused, aquaponics uses about 95 percent less water than traditional farming, only losing what’s taken by the plants and what evaporates instead of seeping into the ground.
Mitchell and Griffin hope not only to sell the plants that they are growing, but the fish as well, once they reach between one and two pounds.
For more information, search for Four Seasons Aquaponics on Facebook or visit fourseasonsaquaponics.com.
Ashley Saari can be reached at 924-7172 ext. 244, or asaari@ledgertranscript.com. She’s on Twitter @AshleySaariMLT.