How to Identify and Treat Calcium Deficiency in Aquaponics Plants

Deficiencies can affect plant growth and make them more susceptible to diseases and insects. Plant deficiencies in aquaponics occur when essential nutrients needed for plant growth are not readily available. One common deficiency that often occurs in aquaponics plants is calcium.

Calcium is essential for plant growth. Without it, plants may rot and have stunted and weak growth. Calcium deficiency in aquaponics systems can seriously impact plants' health, so identifying and treating it quickly is vital. This article discusses how to identify and treat calcium deficiency in aquaponics plants.  

What is Calcium’s Role in Plant Growth?

Calcium is a secondary nutrient that is essential to crop development. All plants need it in large amounts for the formation of cell walls and cell membranes, and it plays a vital role in plant structure. Aside from its structural role, the other function of calcium is its ability to serve as a second messenger in the many developmental and physiological processes of plants ranging from root or pollen tube growth and fertilization. 

What Causes Calcium Deficiency in Aquaponics Plants?

Calcium deficiency occurs when there is not enough calcium in the water and there is too much magnesium or potassium in the water. In addition, calcium deficiency also occurs when your aquaponics crops are not well-ventilated, and the humidity is high. This is because the plants are not transpiring(losing water through plants' leaves) well. If the plants are not losing too much water, they will also not draw much water.    

Calcium Deficiency in Tomato Plants

Signs of Calcium Deficiency

Just like the other plants' deficiencies, calcium deficiency can cause various problems for your aquaponics plants and can have a significant impact on your aquaponics system. So it is essential to know its symptoms for you to act accordingly. Here are the signs of calcium deficiency in aquaponics plants.

  • Black, dead areas of the young plant tissue are known as necrosis.
  • Slight chlorosis to brown or black scorching on new leaf tips.
  • Fresh leaves are distorted with hooked tips and irregular shapes.
  • Premature shedding of blossoms and buds, tip burn, and blossom end rot.

It is important to note that, in some instances, calcium deficiency can imitate potassium and magnesium deficiencies. The difference is the black dead areas of the young plant tissue or necrosis. 

Because calcium can imitate other deficiencies, it is essential to use a key in diagnosing the deficiency.

Usually, necrosis is apparent in the developing areas or at the top of the plant. The young tissue will die first because calcium plays an important role in dividing and building cell walls. If calcium is deficient, new cell walls will not develop, and the young leaves cannot continue to grow.

In fruiting plants like tomatoes, calcium deficiency can be identified by blossom rot, or when necrotic spots appear at the end of the fruit, the blossom is on. 

Treating Calcium Deficiency in Aquaponics Plants

If you are certain that your aquaponics plants have calcium deficiency, here are your few treatment options.

You need to address any issues that affect calcium absorption first by looking into the pH level of the water. Lower pH levels can cause calcium absorption problems and even take the form of calcium unavailable to your plants. Another factor to look into is the sodium levels and changing the water if they are too high, as too high sodium levels can stop plants from up taking calcium. You also need to strike a balance between calcium, phosphorus, and nitrogen, as these nutrients can compete with one another.

After checking the pH and sodium levels, you can supplement calcium into the system by using a hydrated (or agricultural) line. This will supplement both calcium and magnesium and raise the pH levels. Other supplementation options are chelated calcium and calcium carbonate.

Another way of supplementing calcium is by calcium chloride foliar application or by spraying calcium chloride mixed with some water on your plants. The ratio should be four teaspoons of calcium chloride per gallon of water. You can increase the dose if needed, and spray once a week on your plants. The best time for doing foliar spray is early morning or dusk.

Calcium Deficiency In Aquaponics Plants

Preventing Calcium Deficiency in Aquaponics Plants

After treating calcium deficiency and seeing your aquaponics plants return to healthy new growth, you need to take some preventive measures to prevent the deficiency from occurring again. 

Preventing future calcium deficiency in aquaponics is a simple process. It involves balancing nutrients, improving the living conditions of your plants, and being prepared to supplement calcium when needed. Calcium interacts with other nutrients, which can make it more difficult for your plants to absorb. So be sure to balance sodium and phosphorus levels to prevent calcium deficiency. 

The pH levels can also be an issue. Keeping the pH levels from dropping too low will prevent calcium issues. Ensuring proper air circulation to your plants and balancing the humidity will prevent future calcium issues. Lastly, be prepared to supplement calcium as soon as you are sure your plants have calcium deficiencies. 


Calcium is critical to your plant's structure and development, so if your plants are not getting enough calcium, they will stop growing, develop necrosis, and eventually die, which will cause failure in your aquaponics system. So it is essential to prevent calcium deficiency in your aquaponics plants and supplement them with calcium as soon as you’re sure that it is affecting your plants. Thank you for reading our article. For more information on nutrient deficiencies of aquaponics plants, click here.

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