Why Aquatic Plants Fail to Grow and the Correct Planting Methods

In the process of farming fish and shrimp, the presence of aquatic plants is very necessary, but many farmers experience the situation of aquatic plant planting failure, so exactly why do aquatic plants fail to grow? What are the correct planting methods for aquatic plants?

1. Why do aquatic plants fail to grow?

1. Water temperature too high or too low

The suitable temperature for the survival of most aquatic plants is between 18-30°C. Beyond this temperature range, many species of aquatic plants will grow poorly or wither and die.

2. Water pH too high or too low

The physiological phenomena of aquatic plants are affected by the pH of the water. As long as the pH value is too high or too low, the absorption of nutrients and water by aquatic plants will be inhibited, affecting their growth and development.

3. Water hardness too high

Too high water hardness means a relatively high concentration of calcium ions in the water. When aquatic plants live in a high-calcium environment, it hinders their absorption of other nutrients, which is detrimental to the growth of aquatic plants.

4. Unsuitable light quality

The wavelength of the lighting affects the photosynthesis of aquatic plants. For example, among the seven monochromatic lights, only red light and blue light are the most effective for the photosynthesis of aquatic plants. If the content of these two wavelengths in the lighting source is too low, aquatic plants will find it difficult to carry out photosynthesis.

5. Lighting too weak

Although aquatic plants can still carry out photosynthesis under weak lighting, the efficiency of photosynthesis is very low, and they cannot produce the photosynthetic products (sugars) that aquatic plants rely on for survival.

6. Insufficient nutrients

Aquatic plants, like other plants, need fertilizer. Without fertilizer, aquatic plants cannot carry out assimilation and grow.

7. Lack of carbon dioxide

Carbon dioxide is an indispensable raw material for the photosynthesis of aquatic plants. Without enough carbon dioxide, aquatic plants simply cannot carry out photosynthesis. Insufficient carbon dioxide content will reduce the efficiency of photosynthesis, so aquatic plants cannot survive for long.

8. Not aquatic plants but “aquatic plants”

Some water-tolerant plants that grow on land are not suitable for long-term growth in water, but they can survive in water for a period of time, yet ultimately they will still die in the water. These water-tolerant plants usually cannot easily carry out photosynthesis in water; they rely only on the nutrients originally stored in their bodies to maintain the growth they need, so when these nutrients are exhausted, that is the moment they face death.

Originally, this kind of water-tolerant plant should not be sold as an aquatic plant, but because their appearance is very attractive and they will not die immediately when planted in an aquarium, they are often used as short-term arrangement materials for some aquatic plant aquascaping, and are also cultivated in semi-aquatic-style aquatic plant aquascaping. Therefore, some uninformed aquatic plant enthusiasts still buy and plant this kind of water-tolerant plant. Thus, it is recommended to try not to buy this kind of “aquatic plant” for planting; they cannot possibly be cultivated successfully in an aquarium, and can only be used briefly as “living decorations” in aquatic plant aquascaping.

2. What are the correct planting methods for aquatic plants?

1. Tank planting method

Spread fine river sand about 3cm thick on the bottom of the tank, then push aside a hollow, press the fibrous roots into the sand, then weigh down with some pebbles to fix them in place, preventing them from being pulled up when changing the water. This method allows for a very good layout, but cleaning is rather troublesome. This method makes the layout perfect, but cleaning is rather troublesome. It is more suitable for aquatic plants that root at the base, such as Amazon sword (Echinodorus), dragon's beard grass (Rotala), and water chrysanthemum.

2. Pot planting method

This means planting the aquatic plants in a small pot, then placing the small pot into the tank, equivalent to a potted plant in the fish tank. Although this method is relatively easy to clean, the layout is rather restricted. Aquatic plants suitable for tank planting are also suitable for pot planting.

3. Floating planting method

Simply place the aquatic plants into the tank. If you want to fix them in place, you can also press the roots down, tie small stones to the roots of the aquatic plants or slip them into suitable glass tubes and sink them to the bottom of the tank, using small stones to fix the position. This method is more suitable for vine-like aquatic plants that root at the nodes, such as snapdragon (Antirrhinum) and centipede grass (Vallisneria).

Overall, the planting techniques for aquatic plants are relatively easy to get the hang of, so those interested can try it themselves.