The cultivation technique of hydroponic growth is fused with the art of preserving fish in an aquaculture system, resulting in an indoor and outdoor aquaponics system.
The garden plants benefit from both the water that serves as the habitat for the fish and the waste produced by the fish. The water is then returned to the fish tank, providing the fish with refreshed water, while the plants receive the necessary nutrients.
As a result, the clever horticulturist receives natural produce for salads and seafood for barbecuing.
What is Aquaponics?
Aquaponics combines the practices of fish farming, or aquaculture, with the cultivation of plants in a nutrient-rich solution, also known as hydroponics.
Through the aid of beneficial microorganisms, aquaponics systems enable the concurrent cultivation of plants and fish, with all components mutually enhancing each other in an aquaponic environment.
It is possible to cultivate natural food using aquaponics in a self-sufficient garden even with scarce area and supplies.
The path from fish to plants in an aquaponic setup contains a colony of advantageous bacteria that converts fish waste, which is mostly composed of detrimental ammonia and nitrites, into favorable nitrates and other nutrients that support the growth of plants.
Once equilibrium is reached, the self-sustaining system recycles its water continuously as the plants absorb the organic fertilizer and release uncontaminated water to the fish.
Similar to acquiring the skill of riding a bicycle, initial guidance is necessary. However, once stability is attained, it can progress without much assistance.
The scarcity of water has made it evident why there is an increase in commercial-scale aquaponics farming. It is noteworthy that the methods and technology used by large-scale producers were pioneered by small-scale enthusiasts who operated from their backyards.
What Components Make Up an Aquaponics System?
Although the principles are simple to grasp, their execution, including small-scale aquaponic systems for home use, can be either uncomplicated or complicated depending on your preference. It is advisable to begin with an easy approach.
Essential gear comprises tanks and grow trays, along with the necessary plumbing to link them, pumps, and drains. If you’re not cultivating in a moderate climate outside, you must furnish synthetic light and warmth.
Aquaponics has non-sustainable elements such as the necessity for fish food on a daily basis, the electricity needed to operate pumps and the lighting system, and the replenishment of water to account for evaporation and other potential factors, not including leaks.
The tanks and pipes are items that only need to be purchased once. Once set up, this method of growth is environmentally conscious and sustainable, as it requires less fuel, chemicals, and water compared to traditional gardening.
Setting up a DIY system doesn’t necessarily need to be costly. Plenty of individuals who enjoy doing things themselves manage to save money by using plastic barrels, stock troughs, or recycled bathtubs to reduce expenses.
Why Consider Aquaponic Gardening?
Aquaponics, whether small or large, results in a significantly more productive garden. When executed properly, it generates fish and vegetables at remarkable rates, competing with the most rigorous hydroponic and aquaculture productions.
Moreover, it addresses the majority of issues encountered by hydroponic and aquaculture systems by ensuring a consistent and balanced flow of nutrients for plants without the need for extra fertilizers, and simultaneously eliminating the buildup of waste resulting from fish and food in tanks.
Benefits of an Aquaponics System
- One of the best benefits is that aquaponics systems make it possible to have a food production system that’s actually sustainable.
- Protects the environment by using less water and generating less waste and runoff. Instead, the self-contained system recycles its water, removing potential pollutants along the way. Very little water is wasted. Large-scale aquaculture growers are said to use 2% of the water consumed by conventional farming.
- No fertilizer is required. With the help of beneficial bacteria, it’s produced — organically — from fish waste, cutting out fertilizer expenses.
- Easily adapted for home and small-scale needs. It also can be sized for continuous, economically sound, commercial produce production.
- Daily tasks, harvesting, and planting are labor-saving and can be done by most people easily.
- Yields both nutrient-packed carbohydrates and protein in the form of vegetables and fish.
- Fish are not exposed to mercury, PCBs, or other pollutants. No antibiotics or growth hormones of the type used in commercial fish farming are required.
- Makes it easy to grow organic by prohibiting the use of pesticides or herbicides that would harm the fish in the system.
- Fast, healthy growth discourages insect problems, even in greenhouses.
- No weeding required.
- Gardening beds are most frequently placed above fish-raising tanks, bringing them up to an easy-to-work height. No bending or stooping is required.
- Allows for local, small farm growing, even out-of-season. And while local out-of-season growing requires energy in the form of heat and light, it doesn’t compare to the fuel gobbled up by trucks, tractors, and other farm equipment as well as that needed for long shipment and refrigeration of commercially grown produce.
Principles of Aquaponics
The process of converting ammonia to nitrate is known as nitrification.
Although not easily comprehensible, comprehending the nitrogen cycle, the chemistry involved in transforming fish waste, unconsumed food, and other organic materials in the fish tanks to nourish plants, is vital.
Ammonia is released by fish through their gills, with the majority being generated by the fish themselves, while some is produced within the aquarium through the decay of uneaten food and aquatic plants.
Plants require nitrogen, which can be obtained from ammonia. However, the conversion of ammonia to nitrites (NH3) requires two different types of bacteria. The initial step involves Nitrospomonas sp., which transforms the ammonia to nitrites. Although nitrites contain nitrogen, plants cannot use them. Furthermore, even in small amounts, nitrites can be harmful to fish.
Another type of bacteria known as Nitrospira sp. is responsible for the transformation of nitrites into nitrates (although some sources attribute this to Nitrobacter sp.), which can be utilized by plants. Consequently, plants extract the nitrates from the water. As a result, the water is devoid of ammonia, waste, and harmful substances before being reintroduced to the fish.
The conversion process is facilitated by nitrifying bacteria that exist naturally and grow in numbers as conditions stabilize. These bacteria can also be added to systems. Once they are established, they thrive in the grow trays, growing medium, and water pipes that lead to the grow beds. The bacteria create a slime called biofilm in which they carry out their functions.
A sump, which is a container that allows bacteria to proliferate and transform waste, is commonly utilized by intensive growers and those who consume large amounts of water in their fish tanks and grow beds. Before being redirected to the fish tanks, water from one or more grow beds is initially directed to the sump.
Just like in soil, a variety of factors work together to establish optimal conditions for fish, plants, and conversion bacteria.
Ensuring pH Levels Are Adequately Balanced
Keeping pH levels balanced in the water is crucial. Gardeners are aware that the majority of plants thrive in slightly acidic pH. However, fish and helpful bacteria prefer a slightly alkaline pH. Therefore, a compromise must be made by maintaining a pH level between 6.8 – 7.2 in order to keep all three happy.
It is important for cultivators to closely monitor the pH level of their water system, particularly in the beginning stages. During the “cycling” phase, which is when the nitrifying bacteria are developing prior to plants being added, a pH measurement of 7.0 or higher is necessary in a new system.
The addition of plants to the system results in a natural decrease in pH. If the pH level drops below 6.8 and becomes excessively acidic, the waste-conversion procedure will decelerate, leading to the reemergence of nitrites in your fish tank.
Because pH levels vary naturally, growers need to periodically check for ammonia and nitrite levels in their systems. Some types of fish (tilapia) are more tolerant of less-than-perfect water conditions than others. But all do best when conditions are ideal.
Alteration
Aeration is vital for fish tank water to absorb oxygen, which is typically accomplished through water circulation back into the fish tank. However, raising fish intensively may necessitate the use of an aeration device similar to those in aquariums for additional oxygenation.
What Are The Problems With Aquaponics?
Mistakes are bound to happen when undertaking new ventures. Those who are novices in aquaponics tend to make typical errors that result in issues. What are the concerns associated with aquaponics, and how can they be prevented during the initial stages?
Problems with bugs and how to get rid of them
Although aquaponic plants are less prone to bug infestations compared to those grown in a garden, they still encounter such issues. Nonetheless, the use of pesticides, which is a common practice in traditional gardening, cannot be employed in aquaponics due to its harmful effects on the fish.
Many counties around the world consider Aquaponics systems to be organic due to the absence of pesticides and artificial fertilizers. Consequently, it is vital to avoid using pesticides that could harm the fish or negatively impact your health when consuming them.
What is the method to eliminate insects in an aquaponics setup?
Identifying the type of bug in your aquaponics system is essential before attempting to eliminate it. Once you have identified the bug, you can select from these methods to eliminate bugs from your aquaponic plants:
- Introduce bug or insect-eating creatures, like frogs or ladybirds (ladybugs in the US).
- Using organic sprays that are approved by the Organic Materials Research Institute (OMRI) for the appropriate pests and at the right time. That way your produce remains organic, you don’t affect the fish, and the fish and veg are still good to eat.
- Buy a ‘Bug Vaccum’ to vacuum up the bugs.
- Manually remove the bugs and pests and feed them to the fish. Fish love insects.
Overfeeding the fish
Feeding your fish excessively can have detrimental effects such as food wastage and fatal outcomes. It is observed that overfeeding is the primary reason for fish fatalities, as surplus food leads to the growth of waste. Such collection of waste is triggered by uneaten food and additional waste produced by overeating.
Ammonia and nitrites resulting from fish waste can be harmful to them. Even though ammonia is required to be transformed into nitrates by the bacteria in your aquaponics setup, excessive amounts alter water pH.
When you have too much food and fish waste in your aquarium, it creates an additional issue. The decaying process involved is an aerobic process that consumes oxygen and creates carbon dioxide, resulting in depletion of oxygen available for fish to use in the water.
Feeding your fish excessively can result in other fish-related issues such as the development of fin rot or fatty liver disease. Additionally, it can cause problems in the water such as the growth of algae blooms, cloudy water, the formation of mold in plants and gravel, and blockage in your water filtration system if you have one.
To prevent overfeeding of fish in your aquaponics system, it is recommended to employ the following effective methods:
- Feed your fish on a schedule so you don’t forget when and how much you’ve fed them.
- Each time you feed your fish, feed them with a proper amount. The best way to achieve this is to observe how much food they eat when you feed them. If they’re not eating all the food when you feed them, reduce the amount of food.
- Feed based on the number and size of fish in your tank, not on the size of the tank itself.
- Make sure you feed your fish with the correct food for the type of species.
- If you happen to over-feed, always remove the excess food.
- Consider introducing scavenger inhabitants to your aquaponics fish tank. These scavengers will consume any excess food that sinks to the bottom including fish like catfish and loaches.
Overcrowding your fish tank
The quantity of fish in your aquarium is influenced by the species you maintain. Furthermore, you must take into account the variety and quantity of flora you cultivate.
A general guideline for the number of fish to have in your water is for each 25-45 liters (5.5-10 gallons) of water, you can cultivate 450-500 grams (1 pound) of fish.
Insufficient fish to provide the necessary plant nutrients
The symbiotic relationship between the fish and plants must always be considered when dealing with an aquaponics system, as neither can exist independently and rely on each other for survival. Hence, what should be the appropriate proportion of fish and plants?
It is recommended to maintain a fish-to-plant ratio of 1:2, which means two plants for every one fish.
Not testing the ammonia levels and water pH as often as you should
Aquaponic gardening can be easily managed as it requires minimal attention besides feeding the fish. Nevertheless, it is crucial to regularly examine the water’s pH and ammonia levels, which is a vital aspect of the process.
For an aquaponic system to flourish, ammonia that is produced from fish waste is necessary. The primary process in aquaponics involves the transformation of ammonia into nitrites and subsequently into nitrates by bacteria that resides inside the system.
If an excess amount of ammonia is generated and accumulates in the water, it will impact the pH levels and could result in the demise of your fish in extreme cases. To prevent this issue, it is necessary to analyze the water in your fish tank at minimum once a week to evaluate both the ammonia concentration and pH levels in the water.
