The practice of aquaponics is about attending to the delicate balance between plant life and aquatic species occupying the same hydrospace. Anyone who has ever maintained their own fish tank understands the depth of care that goes into keeping the water just right. In nature, the biological elements are designed to comingle together effortlessly resulting in a balanced aquatic ecosystem.
Recreating this natural bioprocess isn’t as easy. It is dependent on nurturing the aquatic environment in such a way that utilizes the nutrients in water to grow plants. In short, this means you must optimize the water conditions. Aquaponics, simply defined, is a system that facilitates a healthy nutrient cascade for both species (plant and fish).
What Contributes to Poor Water Quality in Aquaponic Systems?
Many variables contribute to unstable conditions causing the water quality to remain constantly in flux. Because of this instability, consistent monitoring, upkeep and maintenance is necessary for a successful operation. In many cases, the chemical components associated with a contained aquatic system are not easily controlled.
In worst-case scenarios, late detection of a chemical imbalance can wreak havoc and wipe out an entire aquatic setup. Unfortunately, many harmful micro-organisms thrive in subpar conditions and can spread rapidly before corrective action can be taken.
Some of the more common contributors to poor water quality include:
Equipment failure: These are unplanned events and typically involve power failure or equipment malfunction.
Inadequate aeration: Warm water increases the metabolic rate of most fish species making the need to aerate more important. In some cases, insufficient aeration is the culprit. In nature, water circulation is dynamic and self-adjusting. In artificial ecosystems, slight fluctuations in temperature also require adaptations in aeration needs.
Tank overcrowding: Too many fish in insufficient housing size can throw off chemical balances very easily.
Uncycled food waste due to overfeeding: Uneaten food can result in biowaste residue which can impact chemical levels.
Environmental changes: Exposure to harsh conditions can greatly impact the health of your system such as comprised air quality due to fire or smoke.
Temperature variances: Extreme differences in hot or cold temperatures can greatly impact the health of the ecosystem. Plant and fish are both very vulnerable to big temperature swings or unexpected weather exposure such as frost and heat.
Chemical imbalances: Minute changes in chemical additives have the potential to disrupt the entire aquatic ecosystem. Since each chemical component complexes with the other, subtle changes can have a great impact.
Improper plant/fish selection balance: Selecting the wrong variety of fish or plant species in relation to how they integrate with your chosen design schematic may result in a need for a restart. Too many, or too few of either species (plant or fish) plays as much a role as the type of fish or plant.
Fish stress: Yes. Who knew fish stress was a thing? Well, it most definitely is. Fish welfare is a large factor in aquaponic systems. Fish that can’t grow to their maximum potential can become very stressed. Other considerations include aggressive behavior among tank mates, waste metabolites, and reactions to changes in external stimuli I.e., feeding schedules, tank management shifts, etc.
Is it difficult to maintain an aquaponics system on your own?
Achieving optimal water conditions isn’t rocket science perse. However, when your system isn’t performing correctly, it can feel like it. Since the various chemical components represent the lifeforce of each aquaponics system, a solid testing regime can save a lot of time and money.
We recommend keeping a detailed record-keeping system whether by old-fashioned pen and paper or other sophisticated avenues. Now that agriculture solutions are entering the mainstream, new digital and cloud-based systems exist to help keep detailed records and notes at your fingertips. It can also help forecast potential problems before they happen.
Understand, that there may be a bit of a learning curve associated with getting it all down to a working science. The chemistry involved with aquaponics isn’t going to qualify you for a Nobel Prize or anything, but you will probably get to a point where your friends assign you a “geek” label.
What are the components of a healthy aquaponics system?
New systems are fragile and notorious for nitrate imbalances. It takes a while for the system to produce helpful bacteria and to assimilate to the new conditions. Be patient and make sure you familiar with all the components that are required to start and maintain a healthy aquaponics system.
It may be tempting to use tap water in your system in a pinch – but don’t. The decision of what type of water to place in your aqua system is critical. It can negatively impact the system health in a matter of a few short minutes. Water sources can vary from well water, tap, distilled, or municipal water. It is a good idea to have an ORP probe on hand and to also research which water is best for your unique project parameters. For best results, send a sample of your water to outside lab for a detailed analysis.
The general rule of thumb for most aquatic growers is a pH level of 6.8-7.2. Small variances are to be expected, but careful monitoring is recommended.
High amounts of ammonia can damage the tissue of many species of fish. Conversely, low levels of ammonia can make them susceptible to bacterial infections.
Nitrate and Nitrite Levels
Often confused, two chemical compounds are two distinct elements. Both are commonly found in garden fertilizers and if left unchecked, can wreak havoc in your water-tank. According to the Institute for Systems Biology, the recommended level of nitrate in a stable aquaponics system is between 10 and 150 parts per million (ppm). It is important to note that the recommended level varies by tank size and fish species. Many fish are generally unharmed by high nitrate levels, but it can throw off the balance of the other tank constituents.
In similar fashion, high levels of nitrite may harm your fish. In general, it is advised that nitrite levels be maintained at or below 1 ppm. The organic process of nitrification is dependent upon proper dissolved oxygen levels and the filtering of organic matter.
The measurement of alkalinity is notated in units of milligrams per liter (mg/l) of calcium carbonate. Growing mediums are said to benefit the most from a pH range between 8 and 9, but there are many varying schools of thought about alkalinity and pH levels.
Calcium, phosphorous, magnesium, iron, potassium is complexed into the chemical make-up of an aquatic system. Testing for these elements requires a pH meter to assess whether they need to be added or removed. It Is important to note that pH sensors and meters are not created equal. Learn more about pH sensors here.
Maintaining consistent recommended temperatures is imperative for aqua-health which is generally 18-30° C. Monitoring the temperature can be easily accomplished with the right tools and sensor apparatus.
This is the amount of oxygen contained in the water and measured by a chemical process known as titration. Fish extract oxygen from the water through a bioprocess referred to as passive diffusion. Dissolved concentrations can easily dip below optimal ranges for the fish to convert the oxygen into energy. The result are fish with a reduced rate of growth as well as problems feeding and swimming. Dissolved Oxygen kits are perfect instruments for measuring the DO levels in your aquaponic system.
What is the best design for my aquaponic system?
There are several different methods for setting up an aquaponic system, but the most widely used designs are: the nutrient film technique, media bed, and deep-water culture. It is not uncommon for design schematics to weigh heavily on upon available space, environmental concerns, crop type, and industry experience. Each design features some notable benefits, but also a few drawbacks.
Nutrient Film Technique (NFT)
NFT systems are mainly used in commercial applications. They tend to have lower labor costs associated with them and have an efficient footprint for space-conscious operations. Set ups are scaled upward in a vertical type of format making the design ergonomically friendly. The more common challenges are protecting plants from temperature fluctuations and a tendency for root balls to clog the channeling system. They type of plants grown best in this type of environment are lighter, low-density plants such as leafy greens, herbaceous varieties, and small vegetables/fruits.
These types of systems utilize a medium on the bottom of the container system such as rock media such as gravel or expanded clay (hydroton). They are also commonly referred to as flood and drain systems and are great for beginners or hobbyists because of their simplicity.
Deep Water Culture (DWC)
This is a hydroponic method of plant production where the plant roots gain is immersed in a solution of nutrient rich, oxygenated water as opposed to soil. A hydroponic system is utilized by commercial growers as higher yields often accompany this type of methodology.
Aquaponics is a growing industry and appealing to many beginner hobbyists. The many advanced applications of aquaponics are equally fascinating. They hold many possibilities for a brighter future as agricultural communities globally face increasing issues with farming space, food insecurity, and climate concerns.
We at Atlas Scientific want to partner with our scientific counterparts and help lend our expertise where it matters most. We proudly offer industry-specific scientific tools geared towards small and large-scale aquaponic systems. Inquire with one of our team members about your project needs.
pH probes contain two electrodes (a sensor electrode and a reference electrode) that measure the hydrogen-ion activity in a solution. The exchange of ions generates a voltage that is measured by the pH meter converting the voltage into a readable pH value. The glass electrode was invented by Nobel Prize winner Fritz Haber in 1909,
Temperature sensors are a device used in our everyday lives to measure the temperature of the air, a liquid, and solid matter in a wide range of industries and applications. Temperature sensors are found everywhere. If you have ever received a notification on a hot day that your smartphone has got too hot, that is