Big yields from a small aquaponic system

Most aquaponics designs have the hobbyist in mind and are therefore small and inexpensive to build. But a small aquaponics system in your backyard can mean big fun and profit for those who take it on. A small aquaponic system provides a constant supply of healthier food and considerable savings.

The fish and vegetables that you grow in a small aquaponic system are healthier because it is organically produced. That means you can be sure you’re getting food that’s clean and uncontaminated by the chemicals that farms and food retailers routinely use to preserve and enrich their products.

Here are some of the fish species you can grow in the hydroponic component of your aquaponic system:

• From Australia: Murray Cod, Barramundi, Silver Perch, Golden Perch, Jade Perch, Australian Catfish Species, Sleepy Cod
• From Europe: Brown Trout, Atlantic Salmon, Redfin, Perch
• North America: rainbow trout, catfish, chinook salmon
• Global Species – Tilapia or Carp
• Asian species: grass carp, silver carp
• Ornamental species – Gold Fish, Koi Carp

An aquaponic system is also ideal for a wide variety of plant species. These plants include:

• Culinary herbs: Italian basil, holy basil, Thai basil, coriander (cilantro), chervil, Italian parsley, chives, lemongrass, mint, dill, watercress
• Culinary salad: vegetables and lettuces: romaine lettuce (COS), butterheads, oaks, mache, rockets, icebergs, mezuna, endives, lollo rossas, salad bowl, lollo biondas, bibbs, mescluns, mignonettes, witloofs, radicchios, kales, Spinach
• Asian vegetables: pak choi, bok choi, tatsoi, Chinese cabbage, amaranth, pei tsai, pak choy, choy sum, yu choy

When building your aquaponics system, you will need the fish farming component, the filtration component (both solids removal and biofiltration), and the plant growing component. The fish component is no different from a standard recirculating aquaculture system. It is composed of a tank, a filter element for the removal of solid waste and a biological filter element.

The biofiltration compartment is critical to an aquaponic system because it contains the most important biological entity in the system: bacteria. While fish and plants provide potential income or food sources grown in aquaponics, bacteria are the workhorses of the system. They allow harmful fish metabolite products to be converted into harmless waste nutrients that can be used by plants. This process is important because many species of fish are sensitive to toxins. A good and efficient biofilter will make your aquaponic system run more efficiently.

Regarding the plant growth component, there are several feasible approaches. If you like it as a hobby, you can use gravel beds. The gravel bed of your hydroponic component will act as your system’s biofilter and even solids filter if done right. All you need to do is make sure solids don’t build up and clog the gravel bed. If this happens, the gravel bed will lose its oxygen supply and bacteria will accumulate. This bacteria can then radiate toxins into the system that can kill your fish.