Tips for Monitoring Water Quality in Aquaponics
Water is the lifeblood of an aquaponics system. It is the medium through which fish and plants receive their nutrients and oxygen requirements. It is essential that every aquaponics grower must understand the basic water chemistry in order to manage an aquaponics system properly.
Monitoring and managing your system’s water quality is vital for the health of your fish and plants, as poor water quality can affect the health and productivity of your system. In this article, we provide these tips for monitoring the water quality of your aquaponics system to get the most out of your plants, fish, and bacteria.
Read also: The most common pond problems and how to fix them
Aquaponics Water Quality Parameters
pH
Learn MorepH means “the power of hydrogen,” which refers to the concentration of hydrogen ions in a solution. pH levels can range from 0 to 14, with 7 being neutral. The values between 0 and 7 are acidic, while the values between 7 and 14 are basic or alkaline.
The ideal pH levels for aquaponics systems are between 6.8 and 7.4. These levels are good for fish, plants, and bacteria. Monitoring pH regularly is crucial, as a sudden change in pH levels can be lethal to 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. While a very high pH can cause poor plant growth and fruit and flower development.
How to Adjust pH
To raise pH
To raise the water pH level, use calcium and potassium carbonate. You should add equal parts of each at the same time.
To lower pH
To lower the water pH level in aquaponics, use certain acids, such as nitric, muriatic, and phosphoric. Phosphoric is the safest of the three acids. Rapid pH changes can harm the fish, so adjust and add to the system slowly and wait for it to distribute throughout the system before retesting. You can repeat until your desired pH level is achieved.
Dissolved Oxygen
Dissolved oxygen levels relate to your water temperature: the warmer the water, the less oxygen it can hold. Most aquaponics systems should maintain dissolved oxygen levels at 5 ppm or higher.
In a new system, dissolved oxygen should be measured frequently, but once it is established, you can measure it less regularly.
Low dissolved oxygen levels arise more in commercial aquaponics with high fish stocking rates than in small systems with low fish stocking rates. If the dissolved oxygen is too low, you can increase it by using air stones or a larger pump to increase aeration.
Water Temperature
The water temperature in your system will affect what type of fish you can raise, the biofilter’s performance, and your plant’s 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 at the right temperature for the fish for optimum growth and to avoid fish diseases.
Alkalinity
Alkalinity is a measurement of water’s ability to neutralize acids. It is also called water’s buffering ability, which refers to water’s ability to resist a change in pH. Water with low alkalinity is susceptible to pH changes.
Water with high alkalinity can resist major changes in pH. Alkalinity is measured by titration (an acid known as “the titrant” is added to the water sample). In aquaponics, the level of alkalinity should be maintained at 100 ppm or above.
Ammonia
Ammonia plays a vital role in aquaponics systems. It starts the nitrogen cycle and is an engine of your system’s ecology. Fish produce waste that is full of ammonia. Bacteria convert them into nitrites and then nitrates necessary for plant growth.
Ammonia comes from fish urine breakdown of solid fish waste and is also excreted through the fish gills. In a fish tank, high ammonia is toxic at high levels, but it is necessary to give plants the system the nutrients they need.
Ammonia poisoning in aquaponics fish can lead to:
Damage to fish tissues, especially in gills and kidneys.
Physiological imbalance
Impaired fish growth.
Weak resistance to diseases.
Death
Ammonia and Nitrate Adjustments
Too High Ammonia Levels
Higher ammonia levels occur when more ammonia is produced than can be handled by the biofilters. Possible causes for this are overfeeding of fish, high fish density for the volume of water, or not enough aeration.
Even if your aquaponics system is stable, it is good to check the ammonia levels weekly to monitor and catch changes early and make adjustments before they become a problem. Below are the methods of adjusting ammonia in aquaponics systems.
You can Bring Down the Ammonia Levels by:
Checking the pumps and DO levels.
Adjusting fish feeding rates or the fish density (A rule of thumb is per 2 gallons of water, 1lb of fish).
Increasing nitrification efficiency.
Reducing the quantity of nitrogen going into your system by lowering feeding rates, removing dead fish, and removing uneaten fish feed after feeding.
Too Low Ammonia Levels
If your system lacks enough ammonia, your plants will not grow. So enough ammonia must be produced and converted into nitrate for your plants to thrive. Low ammonia occurs when there are too few fish in the system or too much water for the number of fish grown. The solution to low ammonia levels is adding more fish to your system, increasing feeding rates, or using a smaller tank.
Read also: Top 5 aquaculture trends
High Nitrate Levels
High levels of nitrites could be a sign that not enough plants are being grown to consume all the nitrates produced by the nitrifying bacteria. Adding more plants to the grow beds or adding more grow beds should help to lower the nitrate levels in your system.
Water Source
It is essential to know your water source, as it can influence your system’s water quality. Your potential water source can be well water, surface water, and municipal water. Whatever water source 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.
Your water should be in the pH range of 6.8 to 7.4. If you know that your water source has chlorine, you must remove the chlorine before placing fish in your system. These can be done by purchasing a water purification system, removing chlorine through aeration, or leaving the water uncovered in a container for at least 24 hours.
You can use a chlorine test to check if your water is chlorine free and safe for your fish, plants, and bacteria. A safe level of chlorine is less than 1 ppm.
The most important thing to remember in adjusting water parameters is to make minor adjustments. Making significant adjustments quickly could cause an undesirable and irreversible effect on your aquaponics system.
Tips for Monitoring Water in Your Aquaponics System
It’s best to add water to the grow bed area than directly into the fish tank. This will lower the chances of mistakes and fatal swings that could affect your fish.
Don’t add or remove more than ⅓ the total volume of water in your system at once. You can do one addition in the morning and again at night if you need to top off more than ⅓ in one day.
Maintain pH levels between 6.8 to 7.4 for healthy plant growth.
Removing chlorine and chloramine from your water is essential in maintaining good water quality.
In a newly built aquaponics system, water should be tested daily, so adjustments can be made as soon as possible and weekly in an established system.
Record all your readings in a paper or journal. So you can check your records and will know immediately if there are changes in your water quality.
Read also: The future of fish farming
Conclusion
Whether you’re starting a new system or adding water to your existing aquaponics system, take note that water quality is vital. You don’t need to be a water expert to monitor your aquaponics system. All you need to do is be responsible for taking measurements using the right equipment and doing what it requires, as stated in those measurements.
For more information and updates join our WhatsApp group HERE
Like our page on Facebook HERE
-Advertisement-
We do everything possible to supply quality information for farmers day in, day out and we are committed to keep doing this.
Your kind donation will help our continuous research efforts.
