Filtered Water for Aquaponics Systems
Traditional gardening and farming practices use soil as the medium to grow plants. This time-honored agricultural method can be relatively simple and can produce large yields. Aquaponics, or a soil-free plant growing practice, offers significant benefits. In aquaponics systems, water quality is critical, often requiring reverse osmosis or other water filtration. Reverse osmosis aquaponics gives the grower ultimate control, allowing for healthy plant growth and abundant yields.
Hydroponics vs. Aquaponics
Many people have heard of hydroponics, or the practice of growing plants in a nutrient-rich water solution instead of planting in soil. Hydroponics systems are closed-loop; in other words, these systems recirculate the water solution, which reduces the consumption of water. Hydroponics can be done in the home and garden and has even been adopted for large-scale crop production, such as for salad greens, cannabis, and ornamental plants.
Less familiar to many is the farming practice known as aquaponics. Like hydroponic systems, aquaponics uses water solutions with the right nutrient balance. The main difference between hydroponics and aquaponics is that fish or other aquatic creatures are grown along with plants. In aquaponics, plants and animals form a symbiotic relationship; the plants provide sustenance for the aquatic animals and help to filter the water, and the animals produce nutrients in the form of waste that plants use to thrive. In many ways, aquaponics blends practices of aquaculture and hydroponics into one unified growing system.
What Can be Grown with Aquaponics?
In the home and in larger commercial agriculture operations, aquaponics shows great promise as a method to reduce water use while maximizing yields. A wide range of plants can be grown in aquaponics systems; the most popular include:
- Leaf lettuces
- Cruciferous vegetables (broccoli and cauliflower)
- Leafy greens (chard, bok choy, spinach)
- Ornamentals (violas, orchids, tulips, roses)
Growers with aquaponics systems gain another advantage – the ability to grow and harvest aquatic creatures. These animals grow in harmony with plants in the closed system. While not every animal grown in a reverse osmosis aquaponics system is harvestable, some of the most popular aquatic animal choices include:
- Carp (edible and ornamental Koi varieties)
- Freshwater prawns
Each plant and animal will have its own unique water quality parameters. Growers must ensure the right water composition for their crops, making filtration systems like reverse osmosis very important.
Water Quality in Aquaponic Systems
In aquaponics systems, both plants and animals depend on water quality. Farmers must ensure that the water is free of harmful contaminants, including:
- Heavy metals
- Petroleum residues
- Agricultural runoff
- High levels of dissolved salts
In addition to the potential of contaminants to reach the aquaponics system water supply, the aquatic creatures growing along with plants produce waste. Over time, this waste accumulates faster than plant roots can utilize it, resulting in declining water quality. If not managed, the water solution in the system may become toxic to plant and animal life.
There are several approaches that can be taken to filter the water in aquaponics systems. Most systems rely on some form of chemical or mechanical filtration to supplement the natural biological filtering process of plant roots and animal activity. A reverse osmosis aquaponics system, coupled with water filtration, offers incredible control over the water quality within the system.
What is Reverse Osmosis?
Reverse osmosis (RO) is a mechanical process that mimics the natural cellular process of osmosis. In living cells, water moves through cell walls from areas of lower concentration to those of higher concentration to form a balance. Reverse osmosis uses pressure to push water through a semipermeable membrane; the microscopic pores in the membrane serve as a powerful filtration device, removing sediments, debris, dissolved minerals, and solid waste. A reverse osmosis aquaponics system uses an RO filter between the system and the incoming water supply, either a well or a municipal water source. The contaminants trapped by the RO filter are flushed away through a drain.
Commercial Reverse Osmosis Aquaponics Systems
RO systems are effective in removing harmful contaminants from water, which is beneficial to those using hydroponic or aquaponic systems to grow plants and aquatic animals. A reverse osmosis aquaponics system typically uses a commercial reverse osmosis filtration unit that offers impressive control of water quality. The largest commercial RO systems can process 1000 gallons or more of water per day and feature automatic controllers.
Precision valves allow aquaponics growers to dial in the perfect flow and balance of processed and untreated water. This gives growers the ability to optimize the water profile, or the level of dissolved minerals and ammonium nitrate that both plants and animals need for healthy growth. Commercial reverse osmosis aquaponics systems can remove up to 99% of contaminants, including:
- Pathogens (bacteria and protozoan cysts)
- Heavy metals (mercury, lead, arsenic)
- Suspended solids
RO systems are efficient, effective, and easy to maintain. For aquaponics growers, these systems ensure pure water for the animals and plants growing in the system, which helps to ensure great yields. These powerful water filtration systems are also used in bars and restaurants, food production facilities, bakeries, and pharmaceutical manufacturing facilities.