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The most common plant deficiency symptoms in the aquarium

The most common plant deficiency symptoms in the aquarium

What are the most common plant deficiency symptoms in the aquarium? Occasionally, our aquarium plants show poor growth, yellowing, or even browning of the leaves. In this article, you can read about the causes and possible solutions.

First, it is essential to know that it's pretty standard that in a closed system (aquarium), not everything works optimally for various reasons. It is easy to acknowledge that our aquarium is a constantly evolving and changing ecosystem. Generally, the larger the size, the less it needs external intervention.

Our aquatic plants will show us when there is a problem. Their growth slows, their colors fade, and their leaves die or grow deformed. Now let's go over the reasons why our aquatic plants sometimes die!

Lack of light

It often happens that the lighting in the aquarium is not sufficient for some plants. In such cases, some plants become stretched, and the stems between the leaves (internodes) lengthen. This sparse growth indicates that the plant wants to move towards the lighter part of the surface. Other plants may shed their bottom leaves completely, as they cannot use low-light areas. They don't expend energy on maintaining these leaves but instead discard them and concentrate on the top leaves.

The solution would be to increase the lighting in the aquarium. But be careful because this measure can also promote the growth of algae. Increasing lighting duration is only an option if it is very short to date. The light shouldn't be on for more than 8-10 hours. The ideal lighting period for a modern high-tech aquarium is 7-8 hours a day.

Aquarium plants lighting

Leaf exchange

Many people are frightened by the apparent melting of a newly purchased aquatic plant. Usually, there is no cause for concern. The problem lies in the cultivation process. Potted aquatic plants are commonly grown in modern greenhouses or foil tents. However, in the nurseries, they grow above water in "dry" conditions with high humidity. Most aquarium plants are marsh plants, and as such, they can have an emerged or submerged life. As soon as we place the greenhouse plants in an aquarium, we force them to convert their emersed life into a submerged one. After the plants make this adjustment, they absorb nutrients and photosynthesize submerged. Many aquatic plants, e.g., Echinodorus, have their emersed-grown leaves slowly die submerged. At the same time, they grow new submerged leaves. After the plants make this natural adjustment, they absorb nutrients and photosynthesize submerged. We can observe all sorts of deficiency symptoms on the dying leaves that don't require any intervention (at most, remove the dying leaves). So, nothing terrible happens except we can observe the natural process of leaf change.

Rotala rotundifolia from plant nursery

CO2 deficiency

Carbon dioxide (CO2) is vital for plants. From CO2, they obtain the carbon they need for growth and, not least, oxygen formation. We won't dig deep into the photosynthesis process, as this deserves a separate article. Remember our school days; we may not forget that the presence of light and carbon dioxide is essential for plants and the entire "cycle of life." The presence of carbon dioxide in aquarium water is limited. If plants require more than is available, they will not be able to grow. Some plants can grow with small amounts of carbon dioxide. Still, most need additional carbon dioxide supplied through a CO2 system. Otherwise, they will slowly degrade and stunt. For example, this is the case with most small foreground plants (e.g., Elatine hydropiper). The ideal CO2 level for an aquarium is 20-30 mg/l. You can find more information about CO2 rates here.

Aquarium plants with CO2

Factors limiting nutrient uptake

Plants have difficulty absorbing carbon dioxide and nutrients at high pH and in hard water (above 20 dGH). Therefore, softening water that is harder than the mentioned value is advisable. You can read more about water softening here. In many parts of our country (Hungary), so-called brackish water comes out of the tap. The water is brackish if the KH value is at least as high as the GH value but often higher. In these cases, it is (also) recommended increasing the GH with a special salt like Green Aqua GH Plus.

Plant nutrient uptake diagram

Nutrient deficiency

Retailers hold a wide range of aquarium plant fertilizers. For example, there are fertilizers for aquariums with demanding plants and fertilizers for less demanding plants. Anyway, if there's a lack of nutrients, there are additional supplementary nutrient solutions available. What are the main deficiency symptoms? When identifying deficiency symptoms, we should consider whether the lesions occur on new or older leaves. Use high-quality drop tests to measure deficiency symptoms. You can read more about water tests here.

Iron deficiency symptoms

Although plants don't need a lot of iron, a deficiency is relatively standard. With iron deficiency, new shoots will grow but look dull and yellow. Leaf veins do not fade, distinguishing iron deficiency from other symptoms. The ideal amount of iron is 0.1-0.5 mg/l. You may use additional iron nutrient solutions to increase iron in the water column.

Iron deficiency on aquarium plant

Calcium deficiency symptoms

With this deficiency, leaves deform and become small and pale. Rare, but also found on new leaves. The same symptoms can occur with an overdose of potassium or magnesium. A calcium deficiency almost does not appear in plants kept in tap water. Still, it can certainly happen in aquariums with softened water. We prevent this by adding special salts such as Green Aqua GH+ or Green Aqua GH/KH+.

Other deficiency symptoms appear on the plant's older leaves or the whole plant.

Nitrogen deficiency symptoms

Poor growth of new leaves and yellowing (whitening) of lower leaves indicate severe nitrogen deficiency. The optimum NO3 value is 10-30 mg/l (ratio to phosphate 1:15-30 mg/l F:N). A drop test can check the values, and additional nitrogen fertilization can correct a possible deficit.

Phosphate deficiency symptoms

The growth of the plant slows down, and the older leaves die. Phosphate deficiency is suspected when the plant leaves begin to fade or darken, and green spot algae appear. This plant deficiency is more common in active soils. The ideal phosphate level is 0.5-3.0 mg/l. The phosphate-to-nitrate ratio is also important (1:15-30 mg/l F:N).

Potassium deficiency symptoms

Tiny dark spots on the leaves eventually grow into visible holes. Typically, a symptom of leaf spot disease. The ideal potassium level is 5-30 mg/l. The optimum level of potassium is 5-30 mg/l. To increase the potassium value, use additional potassium fertilizer.

Magnesium deficiency symptoms

The signs of magnesium deficiency can be similar to those of iron deficiency. Pale leaves with dark leaf veins. Magnesium deficiency is only suspected in significantly softened water. Adding special salts such as Green Aqua GH Plus or Green Aqua GH/KH Plus is advisable and will help to prevent this deficiency.

You should not expect immediate improvement once a deficiency has been identified and countermeasures have been initiated. Plants need time to recover; this may take a few weeks. Dead leaves cannot heal. It is always the new shoots that prove whether the change made was appropriate. Finally, it is necessary to show patience, the most crucial weapon of the aquarist!

Do you have further questions or need help?

Our customer service would be delighted to help you if you have further questions about giving your livestock a safe environment. Indeed, we will help you with other questions regarding aquariums and the beautiful world of aquascaping, too!

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