Hydroponically grown plants rely on nutrient compounds added to the water to thrive. Hydroponic gardening that also uses fish depend on the aquatic creatures to provide the needed nutrients naturally. You can combine plant cultivation with aquaponic system to create a truly symbiotic relationship. The plants thrive on the fish waste and clean the water naturally to create the perfect environment for the aquatic creatures to thrive.

What is Aquaponics?

Aquaponics is a combined method of aquaculture that produces fish and other aquatic creatures and hydroponics that make soil-free plants. Vegetables, in return, purify the water returning to fish. Microbials play an essential role in plant nutrition along with fish and their waste. These beneficial bacteria accumulate between the plant roots and turn the fish and solid waste into materials that can be used for plant growth.

Aquaponics is great hope for the sustainable cultivation of organic crops, aquaculture, and water use. Fish waste is recycled and used instead of dumping it into the ocean for plant growth. The water is re-circulated in a closed system that eliminates the consumption of this resource.

Nutrients in Aquaponics

The fish create a consistent level of waste which provides all the nutrients that the hydroponically grown plants need to flourish. In standard hydroponic, you must add nutrients to the water and regularly balance the compounds. Usually, you must change the water every three or four weeks because the percentages of nutrients within the water start to change and cannot be accurately balanced. However, with aquaponics, you never need to change the water because the plants effectively filter out the fish waste for their nutrient supply and in exchange create a clean, oxygenated aqua environment.

Oxygen for Growth

When you combine aquaponics with hydroponics you can expect faster growth and far greater yields. The reason for this phenomenon is the added oxygen needed by both the plants and the fish. Plants thrive with the oxygen around their root system.

You can maximize oxygen with the following methods:

Aeroponics: Spray a fine stream of oxygen and nutrient-enriched water on the plant’s roots within a dark tub.

Flood and Drain: Flood and drain the grow bed with a continuous cycle of nutrient-rich water. The draining lets oxygen in to reach the plant’s roots.

Nutrient Film Technique (NFT) creates a stream of nutrient-rich water down a channel while allowing adequate space for the roots of the lant from the water’s surface and the stem.

Dissolved oxygen (DO) is the amount of oxygen within the water. Fish thrive when the DO range is 5 to 12 mg/L. When the level dips to 4 mg/L or lower than you’ll notice that the fish regularly swim to the water’s surface to gulp air. Oxygen depletion can occur if the water becomes too warm.

Plants also need oxygen for successful aerobic respiration which is the process needed for optimum root growth and nutrient uptake. If a plant does not receive enough oxygen, then it might wilt or show browning/drying roots. Plants need an oxygen level of 4 to 12 mg/L.

You can use air compressors to increase oxygen in your aquaponics system when needed.

Tailoring Fish Feed to Meet the Needs of Plants

With aquaponics, you will need to add iron, potassium, and calcium to the fish for the plants to thrive. Despite needing subtle tweaks, plants are grown aquaponically thrive and far outperform standard those cultivated using a basic hydroponic system. Fish excrement is brimming with nitrogen which enriches the water’s mineral compounds. The plants consume the nitrates and trace elements which they then utilize for vigorous growth. The water is then purified and oxygenated by the flourishing fish. It becomes the perfect cycle that benefits fish and plants.

Water Sustainability

From a sustainability perspective, aquaponics is optimum. The system produces organic crops, healthy fish, and clean water for consumption. The water is never wasted and when maintained in a closed-in system, it is regularly recirculated without any need for changing which is ideal in areas that regularly suffer drought and where water is prized.

Types of Aquaponics System

Aquaponics and hydroponics use the same systems. You can use flood and drain, drip irrigation, water submerged roots, or deep water culture, and nutrient film techniques are all compatible with fish.

Maintaining pH Control with Aquaponics

Maintaining the pH level is an important part of any successful aquaculture process. Three things impact the water’s pH: the fish, the plants, and the bacteria in the water. A neutral pH is 6.8 to 7.2. The waste from the fish causes the water to become acidic so you’ll probably need to use pH adjusters. Plants must have a neutral pH because too high or too low can hinder how they absorb nutrients. Monitor the water’s pH level daily. There is a wide assortment of pH adjusters that are specially designed for aquaponics. Any time you must adjust the water’s pH, take it slowly because many types of fish are sensitive to the variances.

Best Fish for Aquaponics

Best Fish Suitable for Aquaponics

You’ll want to pick freshwater fish varieties such as tilapia or barramundi which best for aquaponics, grow rapidly and tolerate diverse water conditions. Trout are another option. You can also add shrimps and snails to the aqua environment. The fish will thrive on special fish foods and duckweed and lettuce.

As far as temperature and pH are concerned, the fish and plants you choose for your aquaponic system should have similar requirements. There will always be some compromise on the fish and plant needs, but the more they fit, the more success you will have. Fish and plant recommendations include:

• Tilapia
• Blue Gill/ Brim/ Sunfish/ Crappie
• Catfish
• Carp
• Koi
• Fancy Goldfish
• Pacu
• Various ornamental fish such as angelfish, guppies, tetras, swordfish, mollies

Best Plants to Grow in Aquaponics

Pick vegetables that don’t require a heavy nutrient input. Ideally, you should avoid plants that require acidic conditions such as blueberries because the pH needed for such vegetation can harm the fish.

The following plants and vegetables are ideal for growing in aquaponics system:

• Watercress
• Mint
• Lettuce
• Kale
• Flowers
• Leeks
• Spinach
• Radishes
• Cabbage Beans
• Cauliflower
• Broccoli
• Cucumbers
• Tomatoes
• Okra
• Herbs
• Spring onions

Benefits of Aquaponics

  1. Easy way to grow fish and vegetables at once
  2. Reduced water consumption (used about 1/10th of what you would use soil gardening
  3. Water and plans are sustained using the fish waste
  4. No pesticides or chemicals needed
  5. Soil-borne diseases are no longer a problem
  6. Cultivate a large number of vegetables in a small area
  7. Plants grow quicker due to the nutritious, nitrogen-rich waste created by the fish
  8. Fish and plants flourish in the temperature-controlled environment
  9. Water is circulated effectively which reduces water consumption and saves on the water bill

How to Setup Aquaponic Garden

Remember to start small and expand the grow operation as needed.

Here are a few tips on setting up your aquaponic garden:

  1. Always maintain a power source backup to ensure that the water and oxygen pumps continue to pump.
  2. Feed the fish a nutritious diet to ensure that they thrive
  3. Maintain regular food input helps guarantee waste production to feed the plants
  4. Both fish and plants require adequate aeration. Plants must have oxygenated roots and the fish and bacteria also need oxygen to thrive. Large fish require greater oxygen so adjust accordingly.
  5. Always pick plants that have similar requirements as the fish that you will also be cultivating
  6. Remove excess fish waste if needed.
  7. Watch the water pH level.
  8. Do not use pesticides or other substances that can harm fish.

Hydroponics with fish, or simply aquaponics is a successful and sustainable way to cultivate not only plants but also fish in a harmonious environment. All the components of hydroponics and aquaponics complement each other to form an utterly amazing system.