After at least four hours of sleep, I dragged myself out of bed in the wee hours Saturday morning and headed out on a mission to Old World Aquafarm, in Livingston, Texas, some four hours away. After only getting lost once, I arrived before 10 a.m. There I found proprietor Donald Holmes and his assistant Daniel already working on a new deep soil bed that will used for growing root crops, (something most hydro growers struggle with).
Donald, a retired physicians assistant from the Houston area, has been growing crops and fish and experimenting with aquaponics for over five years. Actually his experience with growing fish, shrimp, and crabs goes way back, since he was born into a family of commercial fishermen on the Texas coast.
He has developed his own grow beds and has his own patented filter that sets his system apart. He markets a turn-key system, called the Pro200, that he sells for $3295, that he says will grow enough fish and veggies to feed 4-6 people on an ongoing basis.
Donald had offered to let me build my own system, with his help, on site at his Livingston facility. I wasn’t sure how far we’d get on Saturday, and I arrived prepared to bunk overnight.
When I arrived, he stopped working on his own current build and took a half hour to explain how aquaponics works. There are different kinds of growing systems. Some aquafarmers grow only in non-soil media beds called rafts, which have proven excellent for commercial lettuce growing. Some, like Donald prefer soil. Some systems are a hybrid of both types. There are many options and many opinions, and more than a little disagreement about which style of growing is the best.
It isn’t my purpose here to sort that out. As a newbie, I intend to learn from as many different teachers as I can, and develop my own way of doing things, eventually. Donald builds systems as small and simple as those frequently seen on youtube, made out of IBC totes, and as large as the massive system in his greenhouse, which has tanks as large as above ground swimming pools.
All systems are alike in that they take advantage of certain synergies between plants and fish that exist in the natural world, and use them to enhance food production. Without getting into detail, the plants attract and support the growth of beneficial bacteria which accumulate on the filters (or, alternatively, on inert grow media) in the grow beds. These living filters clean the water for the fish, with the bacteria turning fish waste into useable nitrates that benefit the plants.
After discussing the options, I decided to build a variant of the Pro200 to which I can later add four additional beds. My first system will use an eight foot diameter round stock tank for a fish tank, and when completed will have six 10 x2 ft. soil beds, each with its own large filter. It will require one 2400 gal/hr pond pump, which will both aerate the fish tank and pump water through the beds.
The tank will be bought locally, and I will provide my own GCFI 110V source of electricity (and my own battery back-up if I want one). Eventually I hope to run my system completely off-grid. I will be designing a solar PV array and battery bank specifically geared to providing juice for the Pro200. But for now I’ll use grid power.
Eventually, I should be able to keep about 200 catfish at various stages of maturity in my fish tank, and to grow enough food to provide for most of my family’s basic vegetable and fish needs.
The day’s project turned out to mostly involve building the beds and the filters. To those, I’ll be adding my own tank and the pump Donald had me buy.
After explaining how his system functions and showing me around, I jumped in the truck with Donald and we took a trip to a nearby fish farm, where he took delivery of a hundred channel catfish and fifty or so perch. We took advantage of the ride time to discuss pluses and minuses of various fish, both from a standpoint of species hardiness and maximum food production.
Tilapia are a popular species with aquafarmers, but require controlled temperatures. Catfish also grow quickly, and are less fussy about heat and cold, being a native Texas species. Donald also experiments with growing freshwater prawns (shrimp) and crabs, but freely admits that growing them commercially using aquaponics is not competitive at current prices.
After dropping off the fish we took a lunch break for chicken-fried steaks, and then headed out to Lowe’s and Tractor Supply to get the stuff on my parts list. All the parts were sourced from those two stores, and my bare bones system (sans tank, fish, or plants) ended up costing about $600 for parts (Donald did provide some additional parts and materials he already had on hand, but it didn’t amount to a lot more). The beds were built using 10 ft bunk feeders in which the filters sit on two parallel rods of #3 rebar, which are themselves supported by regular rebar stand-offs sitting on the bed floor. The filters are narrower than the bed floor, allowing enough room for a long loop of perforated PVC pipe to run just underneath the filter, and for soil (separated by a membrane of weed control fabric) to reach the bed floor around the perimeter.
Unlike some systems, Donald’s beds are flooded from below the soil, minimizing evaporation. While there is not complete separation between the incoming and outflowing water, the water does wick up into the soil and drains back through the filters enough to cleanse the water, if the pump is adequate to circulate the entire fish tank volume in an hour.
After our parts trip, we built my beds. Donald and Daniel did most of it, with me assisting on the filter building. Donald’s patented filters are made using several layers of a perforated plastic mesh suspended between sheets of expanded aluminum lathe. I will need to plant my plants and then wait for at least four months (six is standard) before adding fish to my tanks. This allows the filters (really just a scaffold for growing bacteria) to build up the bacteria necessary to cleanse the water and break down the fish waste into fertilizer.
As the sun set on a long Saturday, we loaded my two completed beds, my new pump, and associated plumbing,filters, and miscellaneous hardware for re-assembly into the back of my truck and I drove the four hours home, a little slower this time. In the dark all the way, with a big load strapped down behind me.
I’m no expert after one day of training, but I now feel ready to begin my own learning curve in aquaponics, armed with a load of good equipment and and the benefit of knowledge gained from Donald at Old World Aquafarm. I now know enough to build the rest of my beds myself…but it might be more fun to plan another trip to Livingston and build them with Donald and Daniel.