Aquaculture primarily refers to fish farming, hatcheries, and related production. Yet, it still includes plant-focused disciplines like hydroponics. Some businesses decide to grow both plants and fish, either by keeping them separate with their own water systems or by feeding the fish wastewater through the plants. There are many benefits to attempting dual production of both fish and vegetables/fruit, but it’s not without its challenges too. If you’re still on the fence between choosing plants, fish, or a combination for your aquaculture business, this information might help you make the decision. Choosing unusual plants or fish might pay off too if you have an adventurous group of clients or customers.
Benefits of Fish
Fish are the primary focus in most aquaculture systems and businesses because they can be profitable. When provided with clean water and appropriate food, some fish species can double in size in as little as one month. Warm water fish are often harvested weighing multiple pounds after as little as 6 to 8 months of growth. Decorative species like koi can fetch hundreds of dollars individually, which is rare even with the most in-demand plants. Fish don’t require nutrients in the water like plants do, making it easier to keep the system balanced with automated air and pH sensors. However, fish aren’t in equal demand in all areas and require more processing and handling than plants. Most companies will need to clean and freeze the fish immediately after harvesting rather than trying to sell it live or freshly cleaned. This adds a lot of equipment and secondary containment requirements to the aquaculture business or project.
Benefits of Plants
Many different crops can grow in water alone with the right soilless medium to hold their roots; including tree and shrub saplings. Lettuce and other greens are the most common crops shown in an aquaculture setting, but they’re far from the only options. Tomatoes, cucumbers, valuable ornamental plants, and even bedding plants are routinely grown or started in a hydroponics system. Crops are quicker to grow than most fish, especially specialty greens harvested at the baby stage after only a month or less. Edible crops are somewhat fragile but tend to still need less handling and processing than fish. Fluctuations in water quality or supply are also less likely to wipe out an entire crop of plants, especially if you grow different plants at the same time. Fish don’t need as much light as plants though, and indoor crop aquaculture projects will need costly lights. You’ll find that any money saved on reducing the number of filters and pumps required by fish aquaculture will go to lighting instead. Taking advantage of natural light with a greenhouse is one of the best ways to keep plant aquaculture profitable.
Combining Both for Aquaponics
Aquaponics is the practice of growing both fish and plants in the same system. Only a handful of designs call for raising both lifeforms in the same pond or tank. Most commercial sized designs separate the two so that proper water quality is easily maintained for both. Fish need fresh water at the right pH and temperature. Plants are a effected a little less by pH and temperature, but they need an appropriate amount of nutrients that can be supplied by the fish waste products. Yet releasing fish water directly to the plants could result in too much or too little nutrients reaching their roots. Most aquaponics systems have tanks and testing opportunities in between the fish and plant tanks or ponds to ensure the right mix is reaching both parts. Recirculating systems will also need extra ponds and holding areas at the end of the cycle to allow the water to process until it’s clean enough to send back to the fish. Pumps and biofilters usually play a large role in this part of the process, so make sure there’s plenty of room for equipment and accessories around the edges of ponds and raceways.
The Importance of Fish and Plant Safe Liners
It’s not enough to choose a liner and hope for the best with your valuable fish and plants. Commercial aquaculture systems, in particular, must rely on geomembranes proven to offer both fish and plant safety. Plants absorb chemicals from the water through their roots, and these compounds settle in their fruits and leaves. If the wrong chemical leaches out of a low-quality liner, the lettuce or tomatoes you sell could make someone sick. At the very least, growth is slowed by the addition of these chemicals. With fish, the danger is more direct. The chemicals used to keep some geomembranes flexible and UV resistant are also highly toxic to fish. Choosing a fish safe and plant/food safe liner is essential, even if you only plan to grow ornamental plants and decorative fish. AquaArmor, from BTL liners, is the most versitle liner on the market. It boasts high puncture resistance, is very safe for both fish and plants, is highly UV resistant and can be custom fabricated to your projects specific sizing needs.
Alternatives to Standard Finned Fish
You’re not limited to tilapia and carp for producing fish in an aquaculture system. If you want to stick to standard swimming fare, consider large and slow growing fish like pike and sturgeon. These cold-water species don’t need heaters and can handle a wide range of water quality parameters, but they fetch a high price when finally harvested. Pacu is another trendy option high in demand in some areas. They’re related to piranhas, but they’re not hard to keep, aside from providing a high protein carnivorous feed. Smaller scale aquaculture projects can still generate plenty of profit by focusing on small tropical aquarium fish like mollies, angelfish, and bettas.
Unusual Ideas for Hydroponic Plants
Unless there’s a huge demand for locally grown lettuce in your area, think outside the box when it comes to choosing hydroponic plants. Medicinal and culinary herbs are a popular option because the exact plants you grow are easily tailored to the tastes of your customers. You can reach multiple niche markets without having to expand your business constantly since most herbs take up relatively little space per plant. Growing rare plants to seed in a hydroponics system is a great option for building a business that doesn’t revolve around shipping a perishable product to market in a hurry. Seeds still need careful handling, but they’ll keep for months with little attention, unlike a head of lettuce. Another option is crops that are easily processed into value-added and shelf stable products. Turning peppers into hot sauce or drying herbs will require a commercial kitchen, but it relieves you from the stress of finding a buyer before they go bad.
Don’t be afraid to experiment by adding a small area for either plants or fish on an aquaculture farm. Even if you decide not to integrate the entire system into a combination for aquaponics, you might find a valuable, secondary profit stream for the business. No matter what you choose as your primary product for your business, BTL Liners has the geomembranes to support them. Our liners are both fish and plant safe, so you can always switch production methods later without having to completely re-line your ponds or beds.
