Maintaining an aquaponics system can be challenging and stressful when you don’t have enough experience and knowledge. So it's important to have a clear picture of what is going on in your aquaponics system to know what you can do to maintain the right conditions for your system to work. So we provided this Frequently Asked Questions in maintaining a successful aquaponics system to help you get the optimum returns from your aquaponics system.
Q: How is aquaponics different from hydroponics?
A: Aquaponics is a farming method that combines the growing of plants hydroponically and the raising of fish (aquaculture) in a symbiotic recirculating environment.
Hydroponics is a method of growing plants that use only water and chemical nutrients, without using soil.
The difference of aquaponics and hydroponics:
1. Organic growth - In the aquaponics system, the plants are grown from fish wastes, which is converted by the bacteria into fish food. While hydroponics uses costly nutrients that are made up of a mixture of chemicals and salts to feed the plants.
2. Ease of Maintenance - Once an aquaponics system is established, it is easy to maintain because it is a recirculating environment, you only need to check pH and ammonia levels once a week. You need to check the electrical conductivity daily to ensure that the system is running smoothly.
3. Productivity - With aquaponics, you can have two sources of income (from fish and plants), while with hydroponics, you can only have income from the plants grown hydroponically.
4. Cost of Nutrients- In aquaponics, fish feed is used to provide nutrients to the fish, which is cheaper compared to the chemical nutrients used to feed the plants in the hydroponics system.
5. Less Use of Water- Aquaponics uses less water compared to hydroponics because aquaponics is a recirculating system.
Q: What is the right pH level in aquaponics?
A: Managing pH level in aquaponics is critical because of the three living components (fish, plants, and bacteria) that need to be considered. Plants generally prefer a slightly acidic pH, while the fish and bacteria prefer a slightly alkaline pH. There must be a compromise between the two ranges, so the ideal target pH level is a pH of 6.8 to 7.
Q: How do I lower pH in my aquaponics system?
A: To lower pH levels in aquaponics, it is recommended to use certain acids, such as nitric, muriatic, and phosphoric acids. Phosphoric acid is mostly preferred because it is the safest of the three acids, and it adds some phosphate into the system, which the plants will like.
Avoid using citric acid because of its antibacterial properties.
Q: How do I raise pH in my aquaponics system?
A: To raise the pH level in aquaponics, using calcium carbonate and potassium carbonate is recommended.
Q: How to lower ammonia in my system?
A: To lower ammonia in aquaponics, reduce the amount of nitrogen that goes into your system. You can bring down ammonia by not overfeeding your fish. If the ammonia is high, cut back your feeding process and check if there is a dead fish in the fish tank. Dead fish secretes ammonia, so if you see a dead fish in your fish tank, remove it immediately.
Q: Should I clean the green slime that covered the side and bottom of my tank?
A: No, we don’t recommend that you clean it off, because the green slime is a biofilm. Biofilm only grows as a thin layer on the surface of the tank, and it causes no harm to the fish and the system. It helps in keeping the beneficial bacteria in the system.
Q: My water turns green. What should I do?
A: These are suspended algae, and this usually happens in setting up a new system. This is a natural phase that occurs as your system goes through the cycling process. Pump full time and stop feeding your fish. Cover the top of your fish tank to keep the light away from the water.
Q: What should I do If I have algae in my grow bed?
A: Algae, if not managed properly, can impact the nutrition and pH of your system. One of the easiest methods of reducing algae in your system is by shading your fish tank. Algae needs light to grow and reproduce, so simply use a dark-colored tarp or piece of plastic to cover your fish tank. Another way to solve this problem is by putting worms into your grow bed. Composting worms helps consume uneaten food, algae, and old dead roots in the grow bed.
Q: How do I keep the water temperature right for the fish?
A: There are several ways to keep your water temperature right for the fish. First, start with the location of your fish tank, if the fish tank is in hot or cold condition, consider insulating your tank, as this will help in keeping the water from fluctuating. Second, get an aquarium heater that turns on and off on certain temperatures.
Q: How much should I feed my fish?
A: It is important to balance the amount of feed entering the system for the overall success of an aquaponics system. Calculate the amount of feed that is needed in your system by using this formula; 20 g of feed per square meter of DWC growing area.
Feed only the fish with what they can consume in 5 minutes and remove any uneaten fish food to avoid unwanted water quality issues.
Q: How do I avoid fish diseases in the aquaponics system?
A: To avoid fish diseases in your system, keep your water moving, and aerated. You can also keep your fish healthy by keeping the water clean and free from solids build-up like uneaten fish food. Also, do not overfeed your fish and avoid stressing the fish in your system. Choosing the best fish for your aquaponics system will play a key factor in avoiding fish diseases.
Q: How do I control plants diseases and pests?
A: Prevention is better than cure. The best thing you can do to keep your plants healthy is to make sure your aquaponics system runs well, with enough nutrients to feed the plants. Avoid nutrient deficiencies in your system. Healthy plants repel diseases, and pests. However, if problems with pests occur, you cannot use pesticides as this will affect the health of the fish. Plants with pests and diseases are usually removed in the system, and replaced.
Q: How do I cycle my new aquaponics system?
A: These are the steps to get the cycling process going on in a new aquaponics system:
1. Add water to your system ( no plants or fish at this stage) and turn on the pump. Let it run for 2-3 days. (This is important if you’re using chlorinated water, which takes up to 24 hours to dissipate)
2. Add some fish, and these fish will generate ammonia.
3. You can also start adding some plants to your grow beds at this time.
Over the first 10-15 days, the ammonia will gradually rise to a peak, because at this stage, the beneficial bacteria (Nitrosomonas) is establishing in the system and start converting ammonia into nitrite.
Then at 25 days into cycling, the nitrite level will be at its peak because another beneficial bacteria (Nitrobacter) enters the system and converts nitrite into nitrate. By 40 days or more, your system should have zero or less than 1 mg ammonia and nitrite but have high nitrate levels. Once you reach this stage, your system is fully cycled, and you can start adding more fish and plants to your system.
Q: How do I cycle my system without fish?
A: Steps on how to do fishless cycling in your new aquaponics system:
1. Add ammonia to the fish tank a little at a time until you have an ammonia reading of 5 ppm.
2. Record the amount of ammonia that you add and add that same amount of ammonia daily until nitrites appear at 0.5 ppm.
3. Once nitrites appear (5-10 ppm) and the nitrates have dropped to zero, you can start adding your fish and plants.
Q: What are the types of water pumps?
A: Water pumps play an important role in the aquaponics system by making sure that the water in the system circulates properly so that both fish and plants receive their required nutrients to live and thrive in the system.
The two types of water pumps are; submersible pumps and Inline pumps. Submersible pumps sit directly in the tank and pump the water through a hose attached to the fitting at the top of the pump. They are usually sized in Gallons Per Hour (GPH).
Inline pumps are air-cooled pumps that sit outside the fish tank. Inline pumps have higher-powered motors that are capable of moving larger volumes of water. They are usually measured in horsepower (HP), not by the volume of water that they can move. Inline pumps often have a tube from the tank to the pump, and another from the pump to the grow bed. Inline pumps are usually used in large or commercial aquaponics systems because of their ability to move large volumes of water.
Q: What size of water pump should I use in my system?
A: Almost all pumps have a GPH rating that lets you know the number of gallons that it can pump every hour. The water pump should circulate the entire volume of water in your system at least every two hours, so it is important that the pump you choose can meet this requirement.
So let’s say:
- If you have 500 gallons of water in your system
- You will need a pump that can circulate 250 gallons of water per hour
- So, you will have to look for a pump at least 250 GPH
Another way of determining the size of the pump is by measuring the head height of your aquaponics system. You can do this by measuring the distance between the two water levels with a tape measure or ruler. Always remember that the larger the head, the more energy is required to pump the water. Keeping the head at a minimum level will keep the whole system efficient. As a rule, it takes about 1 PSI to raise the water level to 2.2 feet.
Maintaining an aquaponics system can be challenging at times, but that is a part of aquaponics gardening that every aquaponics gardener must experience to learn. These challenges can be solved if you have the necessary knowledge about aquaponics before starting your system. Our website has lots of free aquaponics articles that can help you in maintaining your aquaponics system. So, join our mailing list to get new aquaponics updates and articles that can help you to successfully maintain your aquaponics system.