Last updated on October 23rd, 2023 at 08:33 pm
The Elodea impresses with functional attributes, rather than with decorative flowering beauty. As a lush green, hardy underwater plant, it makes a constructive contribution to maintaining water quality in the pond and aquarium.
At the same time, it serves as a valuable source of oxygen, a popular spawning ground and a popular hiding place for fish. Thanks to their high nutrient consumption, Elodea species hardly give undesirable algae a chance.
However, their invasive character should not be underestimated, as the strongly branched shoots proliferate at breathtaking speed. Consequently, it is advisable that gardening enthusiasts and aquarists concern themselves with the requirements of their care, so that the water plant does not mutate into a ‘green ghost’.
Contents
Care in the pond
Unlike a large number of pond plants, such as the native floating plants, elodea is not protected by law. Hobby gardeners who want to establish Elodea in their own water world can therefore cut the shoots from a plant in the wild and transport them in a water-filled plastic container without a guilty conscience. The water plant is so vigorous that even a small piece of a shoot without roots is enough to create an underwater forest within a short time. Of course, the specialized trade has the robust water plant almost all year round for garden lovers to buy.
- Stick a piece of plant in the bottom of the pond or simply place it on the water.
- elodea requires a sunny to semi-shady location.
- Ideally, the water quality should be clear and clean.
- Elodea thrives even in murky, slightly polluted pond water.
- Only if deficiency symptoms appear, fertilize.
- Special fertilizer for pond plants in liquid form is suitable.
- Regular shortening and thinning of the stems limits the spread.
If there are other underwater plants in the pond, there is a risk that they will be overgrown by Elodea. The experienced gardener prevents this by placing these plants in a planting basket. From time to time he takes out the baskets and removes any overgrowth by the Elodea , simply pulling out the unwanted parts of the plant.
Wintering
Except for the Argentine water plant, the other Elodea species are hardy without restrictions. The shoots turn brown and sink to the bottom. Provided the pond does not freeze over completely in winter, new shoots will appear from early spring and rise towards the water surface.
Since the dead shoots no longer contribute to the oxygen supply, they threaten to pollute the water quality by rotting in winter. Consequently, the experienced gardener fishes off a large part of the underwater forest in the fall as a prophylactic measure. The vigorous elodea is not affected in this way, but continues to thrive in the next season. Most of its biomass does go dormant and turn brown; however, some winter buds remain at the bottom of the pond, from which the elodea resprouts in the spring.
In regions with mild winters, the evergreen Argentine elodea has a good chance of surviving the cold season in good health. Where frosty winter periods are expected, it is advisable to place the plant so that it is deep enough in the water to avoid falling victim to the first frost right away. Since it does not go dormant like the other Elodea species, this species has a need for light at all times of the year. If a thick ice cover closes over it while the water temperature constantly does not exceed 4° Celsius, the Argentine elodea will die.
Care in the aquarium
Among the plants for the aquarium elodea is one of the classics. It brings fullness to the appearance, keeps the water free of algae due to high nutrient consumption and serves as:
- Retreat
- Spawning place
- Food
- Oxygen supplier
Experienced aquarists use Elodea as a background plant because its rapid growth would quickly block the view of the colorful aquatic world. It is its busy growth habit that makes care in the confined space of the aquarium somewhat more involved than in the garden pond.
Plant or let it float
Once the decision has been made to incorporate elodea into the aquarium, there are two options to choose from:
Plant using the traditional method.
- Defoliate the ends of several stems on a short piece.
- Plant only the leafless parts of the shoots.
- Make sure the elodea is in the background.
Let Elodea drift
- Useful for cultivation in bottomless propagation tank.
- Simply lay out the young plant on the water surface.
For aquariums designed according to a formal structure, loose Elodea floating on the water surface are rather unsuitable. On the one hand, the plant will constantly strive to root itself in the soil, as in the garden pond. In addition, it could cause excessive shading of the other plants, which is detrimental to their growth.
The right lighting
In the wild, the sun provides the vital supply of light to plants. In the aquarium, artificial light sources are sometimes required, the intensity of which must be carefully dosed to ensure that the water plant thrives optimally.
- A light intensity that meets the needs of the plant promotes leaf growth on the stems.
- In a bright location, the elodea is content with indirect light.
- If there is a lack of light, additional lighting is provided by LED, T5 or T8 lamps on an hourly basis.
- Direct sunlight on the aquarium should be avoided at all costs.
In order to adapt the shape of the lamp to the interior of the apartment, aquarium lighting can be purchased in various designs, such as pendant, spot or surface mounted.
The proper substrate
An essential requirement for healthy plant growth in the aquarium is the condition of the substrate, which should be as close as possible to natural specifications. Although elodea is quite flexible with respect to temperatures, it does not fare well if cultivated in an aquarium that has a tropical heat in the upper part due to a rod heater, while room temperature prevails at the bottom.
- Use a bottom heater with integrated bottom flow in the aquarium.
- This creates uniform temperatures and water movement.
- At the same time, the water plant will be better supplied with nutrients.
- Only use specific mixtures from the specialist trade as substrate.
Aquarium beginners in particular tend to use pond soil or even potting soil as substrate. However, since conditions in the confined environment of an aquarium are completely different, this decision can prove fatal. Not only for the water plant, but for all other plants in the aquarium, it is more beneficial to use professional substrate from the beginning, based on nature’s model, with quartz sand and clay minerals.
Fertilize
Plant using the traditional method.
- Defoliate the ends of several stems on a short piece.
- Plant only the leafless parts of the shoots.
Let Elodea drift
- Useful for cultivation in bottomless propagation tank.
- Simply lay out the young plant on the water surface.
If the water plant loses its rich green color and continues to lighten constantly, it is not doing well. If the other environmental conditions in the aquarium move within normal parameters, the suspicion is that there is an undersupply of nutrients. As in the garden pond, the aquarist only reaches for a fertilizer preparation when indications of malnutrition of the elodea become apparent.
Do not use commercial garden or flower fertilizers.
The calcium, magnesium and nitrate they contain are already present in tap water.
Modern aquarium fertilizers are correctly dosed and water-soluble over a long period of time.
To prevent overfertilization, which would immediately open the door to an algae bloom, experienced aquarium operators use daily fertilizers, which ensure a sufficient supply over 24 hours and whose administration can be stopped immediately as soon as the deficiency symptoms of Elodea species disappear.
CO2 supply
Plants in the wild take the most important nutrient for their growth, carbon, from the air. Since elodea in the aquarium only has the CO2 dissolved in the water available, this supply is quickly depleted due to the confined space. In the worst case, the chemical administration of carbon causes the pH to rise to the upper, alkaline regions, which is not good for a elodea or the other plants and creatures. Consequently, foresighted aquarists, only the gaseous administration of CO2 comes into question. For this purpose, a suitable device for every volume is available in the specialized trade, from the inexpensive starter set to the fully automatic professional system, which permanently measures the CO2 content and releases the carbon as required.
The amount of CO2 required in the water depends on various factors, such as plant density or fish population. Experience shows that the value should not fall below 5 mg per liter of water and ideally should oscillate between 10 mg and 20 mg per liter.
Conclusion
Despite its invasive nature, elodea should not be missing from any pond or aquarium. Its valuable contribution to maintaining or improving water quality, as well as being an impressive oxygen supplier, clearly outweighs its drawbacks. By regularly pruning and thinning out the underwater forest, pond owners and aquarists keep the proliferating Elodea in check. In the context of cultivation in the garden pond, the amateur gardener is forced to react to external influences. In the aquarium, he actively influences growth through the use of artificial lighting, targeted administration of CO2, the use of bottom heating and bottom flow, as well as a species-appropriate substrate.