There are three living organisms in an aquaponics system. These are the plants that grow vegetables or fruits, the fish that provide foods for the plants, and the nitrifying bacteria that convert fish wastes into foods for the plants. But how does light, water, and oxygen affect these three organisms to live and thrive in an aquaponics system?
Let us take a look.
Light
Light is essential for plant growth. All plants require sunlight for photosynthesis, which converts light, oxygen, and water into carbohydrates (energy). This energy is needed by the plant to grow, bloom, and produce fruits. Without enough light, plants cannot manufacture carbohydrates, and plants will die.
Sunlight is the best source of light for the plants in an aquaponics system. However, if you decide to grow an indoor aquaponics system, you can use artificial light to supplement your plant's light needs. Artificial lighting needs to be given essential considerations and carefully selected because plants absorb wavelengths at either end of the light spectrum which we cannot see.
Although plants require light, fish prefer some shade. Fish do not need sunlight to grow and survive, but most fish require both light and dark periods. Without periods of light, the fish may become lethargic and become ill or may stop eating. So you must provide light (artificial or indirect sunlight) to your fish every day.
So even if you plan to have an indoor or outdoor aquaponics system, you need to provide the three living organisms enough and balance light for them to thrive.
Types of artificial lights:
- Fluorescent Grow Lights are relatively inexpensive but are typically only adequate for low-profile plants like leafy greens. Fluorescents are great for seed starting and lighting rectangular beds up to 4' in length. These grow lights are low heat lights, so you can put your bulbs close to your plants, making it ideal for low ceiling growing spaces.
- High-Intensity Discharge (HID) Grow Lights are suitable for all varieties of plants. HIDs are more efficient than fluorescent lights and a much better choice for more extensive and more demanding indoor plants. HID light has an awkward shape and is often used in conjunction with a reflector which directs the light down towards the plants. HID setups are generally configured with interchangeable ballasts, reflectors, and bulbs so you can mix and match the components to fit your style or budget.
- LED Grow Lights are the best on the market today. This is because LED manufacturers are getting control over the spectrum of light emitting out of LED fixtures by fine-tuning the range of LEDs on the panel. LED fixtures are more energy efficient compared to other grow lights. Using LED in your indoor or greenhouse aquaponic garden has many advantages making LED our best choice as the best grow light to use.
Water
Water is the lifeblood of aquaponics. It moves the fish waste from the tank into the filter and recirculates nutrients from the filtration to the plants. Good quality nutrient-rich water provides a perfect environment for the bacteria to thrive and nitrify to keep the water safe for the fish.
The water quality in an aquaponics system is essential because it ensures the growth of healthy fish and plants. That is why it is necessary to monitor the water quality of your aquaponics system for your fish and plants' health. Temperature, PH, water source, and ammonia are the water qualities you need to pay close attention to.
pH is the scale that represents acid, neutral or alkaline conditions in the water.
pH means "the power of hydrogen," and it refers to the concentration of hydrogen ions in a solution. In aquaponics, it is ideal to keep your pH levels between 6.8 and 7.4, which is the compromise for the fish, the plants, and the bacteria. This level will keep the bacteria functioning at high capacity while the plants prefer a more acidic environment.
Monitoring pH regularly is crucial, as a sudden change in pH levels can be lethal to both the fish and plants. If pH levels in your system get too low, the nitrification will slow down or stop, and ammonia will accumulate to a level that is toxic to the fish. A very high pH can cause poor plant growth and poor fruit and flower development.
The water temperature in your system will affect what type of fish you can raise, the bio-filter performance, and your plants' growth.
Fish are temperature dependent. Goldfish, tilapia, bass, and catfish are warm-water fish and prefer a temperature ranging from 65° to 85°F, while trout are cold-water fish and thrive in temperature ranges of 55° to 65°F. Your water should be the right temperature for the fish for optimum growth and to avoid fish diseases.
Water is a crucial parameter in monitoring your water quality. It is essential to know your water source as it can influence the water quality of your system. Your potential water source can be well water, surface water, and municipal water. Whatever source of water you use, it is essential to test it for a water quality profile to ensure that your water meets your fish and plant water requirements.
Ammonia comes from fish urine, breakdown of solid fish waste, and it is also excreted through the fish gills. You need to closely monitor the ammonia level in a fish tank because high ammonia levels are toxic to the fish.
Oxygen
Oxygen For The Fish
Plants and fish need oxygen to thrive. That is why it is essential to ensure that you maintain the right oxygen levels in your aquaponics system. Most fish species will grow and thrive within a DO range of 5-12 mg/L. Too low oxygen levels in aquaponics will cause fish stress, stunted fish growth, or even fish death. Unhealthy fish in the fish tank may create a domino effect that could be detrimental to the system.
Oxygen depletion usually happens during summer months because warm water holds less oxygen than colder water. Warmer water increases the metabolic rate of fish, resulting in the need for more oxygen. So if you live in a warmer climate, you need to aerate the water well.
Oxygen for the Plants
Plant roots need oxygen for aerobic respiration, an important plant process that releases energy for root growth and nutrients' uptake. Inadequate oxygen supply will cause the roots to wilt under warmer climates or high levels of lights. Insufficient oxygen also reduces the root's ability to absorb the nutrients and minerals in the water that is necessary for plant growth. The recommended oxygen level for the plants in an aquaponics system is 4-12 mg/L.
Adding Air Pumps to the Fish Tank
Be careful in monitoring and maintaining your aquaponics system. Keep track of any fish that is sick or dying. This could be an indication of low levels of oxygen in the fish tank. This problem should be addressed immediately by adding an aerator.
Summary
Understanding the role of light, water, and oxygen is a must when running a successful aquaponics system. In maintaining and monitoring your aquaponics system, you must invest in a good quality water test kit to ensure that you have reliable water test results. Thank you for reading. Subscribe to our newsletter below to be notified when our new articles are published.
