Main causes of plant diseases.
Continued…
The roots of certain plants, especially Barclayaceae and a number of *Cryptocoryne* species that grow in nature in so-called anaerobic conditions—meaning dense, muddy soils where oxygen access is limited—suffer greatly during transplantation and prolonged exposure to open air. In such cases, they quickly rot away, the plant floats to the surface, and it often dies.
Therefore, it is better to wrap the roots of such plants together with the surrounding substrate in a dense, oxygen-impermeable plastic bag without taking them out of the water (i.e., right underwater). When planting such plants in an aquarium, it is also advisable to avoid contact between the roots and atmospheric air. To do this, the packaged plants are first submerged in water, and only then is the packaging unwrapped, the root system placed into a pre-prepared hole, and covered with substrate. The quantity and quality of the substrate must match the specific requirements of individual plant species.
The almost complete absence of oxygen in the lower layers of the substrate indicates a low redox potential (rH) of the water, which must also be taken into account when moving plants from one aquarium to another and when cultivating similar species. Increased water circulation, powerful aeration, ozonation, as well as the dissolution of hydrogen peroxide or potassium permanganate in the water (used to combat algae and fish diseases), lead to an increase in the redox potential. This must be taken into account when analyzing your successes and failures.
Many plants in aquarium conditions require fertilization. Due to a lack of nutrients in the substrate, they can wither and weaken. Holes appear on the leaves, the edges lose their smooth shape, and the coloration becomes pale. Potassium is one of the main nutrients needed by plants in large quantities, along with nitrogen and phosphorus, making it an essential condition for healthy plant growth. Micronutrients such as iron and manganese are also crucial for plant growth, though they are required in very small amounts. Their deficiency leads to various problems, such as loss of leaf coloration and the formation of enlarging holes on the plants even while they continue to grow.
Floating plants are susceptible to aphids, spider mites, and scale insects. To remove them, the plants are transplanted into a separate container with water and sprayed with a special solution. For aphids, repeated spraying of stems and leaves with strong infusions of garlic, onion, tobacco, green soap, or copper sulfate is effective; for scale insects, wiping with a soft toothbrush dipped in a soapy-kerosene emulsion (a tablespoon of laundry detergent or plain soap and slightly less kerosene diluted in a liter of warm water) works well. After the insects die, the plant should be thoroughly rinsed under tap water.
A strong water current created by a directed jet, while favorable for fish development, has an inhibitory effect on plant growth. It contributes to the formation of deposits on the leaves and degrades the appearance of the plants.
Before planting, each plant must be cleaned of attached filamentous algae, snail eggs, decaying parts, etc. Afterward, it should be disinfected for about 20 minutes in a pink potassium permanganate solution. A bath (5 to 10 minutes) in an alum solution (1 teaspoon per 1 liter of water) or rinsing with hydrogen peroxide (1 teaspoon per 1 liter of water) is also recommended. Then the plants should be gently rinsed.
Roots can be slightly trimmed to stimulate prompt growth. For plants with a small number of thin roots, they are either left untouched or trimmed very moderately (the roots of *Anubias* are not touched). It is impossible to preserve the original roots of aquatic plants. The massiveness of roots in newly purchased aquarium plants is not critical for their future life, as the old roots will generally die off anyway.
The most important micronutrients include manganese, molybdenum, copper, zinc, and boron. Tap water most often lacks micronutrients or contains them in very small amounts. They should also be added to the aquarium water bound to chelates. Calcium, magnesium, and sulfur are present in sufficient quantities in tap water, provided it is not overly soft. The amount of potassium in tap water can vary, but its deficiency is sometimes noticeable. Therefore, aquarium fertilizers contain potassium. Iron in this context is not a micronutrient. It is one of the primary macronutrients that plays a vital role in plant cultivation, participating in the formation of plant chlorophyll. In case of iron deficiency, plants can no longer produce chlorophyll and, consequently, cannot assimilate organic substances.
Most macro- and microelements are contained in complex mineral fertilizers. Mineral fertilization should be applied periodically. This is best done during regular water changes once a week or every ten days. Fertilizers are added to the replacement water, the volume of which typically constitutes 1/5 to 1/4 of the aquarium’s volume.
One of the simple ways to reduce nutrient concentrations is heavy water changes, provided that the replacement water does not contain an excess of these elements. However, this method is not effective for all elements; the concentration of certain micronutrients (manganese, copper, etc.) drops rapidly after introduction. On one hand, this is due to rapid uptake by plants; on the other hand, it results from the formation of insoluble salts or complex compounds with the organic substrate in the soil. Sparingly soluble phosphates can also accumulate in the soil. In these cases, regular water changes will not effectively remove excess nutrients. Therefore, the most reliable way to avoid overdosing remains precise calculation of the applied fertilizers without exceeding recommended doses, combined with careful observation of the plants.
However, the main key to disease prevention is optimal maintenance conditions, hygiene, and careful daily care. Generally, an unhealthy ecological environment is caused by fish overcrowding, a dirty filter, water acidification due to high nitrates, or overfeeding. Regular water changes, especially during warm weather, a good and timely cleaned filter, a small number of fish, and substrate cleaning will add health and beauty to the plants. If the aquarium is maintained in good condition, aquarium plants never get sick. Many plants are sensitive to medicinal treatments used for fish diseases, so read labels carefully.
Some signs and causes of diseases.
