Research shows that live plants are much more than decoration for freshwater fish. Studies find that the majority of freshwater community aquarium fish prefer live aquarium plants to their plastic counterparts. This is no doubt because live aquarium plants are a key part of creating a natural or close-to-natural environment for most freshwater aquarium fish. Unlike plastic plants, live plants will remove carbon dioxide from the water, utilize nitrates, and add oxygen.
In a well-planted aquarium, fish can find shade from glaring light, privacy from things outside of the tank that startle them, and a natural safety in times of stress. Live plants allow smaller, shyer fish to evade larger or aggressive tank mates or overeager potential breeding partners. For shoaling fish, plants give the group the currents and eddies they instinctively seek out in the wild.
When breeding many species, live aquarium plants are essential surfaces for the deposit and fertilization of eggs. Live aquarium plants have natural infusoria and other essential algae clinging to them or growing from them that feed the newborn fry of many species.
Care and Needs of Freshwater Aquarium Plants
Live aquarium plants need three basic things to stay healthy and provide important benefits in the aquarium environment.
- Sufficient lighting simulates the positive properties of the sun for plant photosynthesis. The deeper the tank, the stronger the lighting system needed.
- The proper substrate keeps live plants anchored and provides a fertile area for root growth. Fine gravel, specially designed terracotta gravel, or sand works best for a live plant environment. Never use dirt or loam soil of any kind in a freshwater community aquarium environment. “Dirt” or “pond mud” can breed harmful bacteria unless sterilized, and if sterilized, the loam is of little or no use to plants.
- To provide sufficient food for the live aquarium plants, a well-established freshwater aquarium will have some nutrients in the substrate. A new aquarium must be supplemented with live aquarium plant food which is widely available in pet stores. Even well-established aquariums should be supplemented with extra plant nutrients for maximum benefit to the community aquarium as a whole.
Ground Cover Plants
Vallisneria and other ground cover plants send out “runners” which develop into new rooted separate plants. These new plants can be broken off as they mature and moved to another location in the tank or another aquarium entirely as a new fully-viable plant.
These true aquatic plants are great for ground cover and should be placed in the rear of the aquarium since most species grow tall. It must be noted that these “true aquatic” plants cannot tolerate a dry condition, so do not remove them from the aquarium and allow them to dry out as this will severely damage or kill them. Even moving from aquarium to aquarium or from store to home aquarium should be done in a container of water. Air damage can occur quickly and makes plants unattractive for weeks.
Myriophyllum, Ludwigia, and Acorus, as well as many other plants commonly found in aquarium stores, are node propagators. Their long stringy branches easily break off and float on the surface of the aquarium. These loose branches can be gathered in a small bunch, anchored with a weight strip and planted firmly in the substrate; the new “clump” of branches will soon root and become a new complete plant.
When a branch breaks off several new branches will grow out from the leaf nodes, making the plant thicker each time it is broken or clipped. If you choose to clip the plant, cut the branch close to a set of leaves, as roots grow from the node where the leaf connects to the branch.
Aquatic Plants from Bulbs
Bulbs can be dried from some aquarium plants and planted. Dry and seemingly dead, under the substrate, once planted underwater, these “bulbs” will quickly sprout and grow very fast under the right conditions. The Madagascar Lace is a prime example of this type of aquatic plant. These plants, also available in aquarium stores from time to time, are easy to grow and can be very attractive.
One drawback is that they have a definite growing season. They will grow and put out leaf after leaf from the base at a central core until finally, they produce a flower of sorts in the center of the core. Once a “flower” has been produced, the plant will go into decline and seem to die. The plant has not died, it is dormant; in nature, it would stay dormant through the dry season, storing its energy until the next rainy season.
When you see this type of plant go into decline remove the “bulb” from the aquarium (sometimes there will now be two or three bulbs when you dig it up from the substrate). Dry it and keep it in a cool dark place for at least three months. If there are multiple distinct bulbs, separate them. Plant the “bulbs” the same way you did it originally and observe the cycle again.
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Aquatic Plants That Propagate by Seed
Some aquatic plants propagate by seed, but most of these are not true aquatics. Some underwater plants, like the Amazon Sword Plant in its many varieties, can grow out of the water or under the water. As with the “bulb” type plants, this is nature’s way of ensuring that a plant will live through a cycle of wet and dry seasons. These plants cannot be propagated by drying and replanting seeds that eventually appear after a flowering stage; most of these aquatic plants reproduce by sending out runners.
Plants That Grow Both in and out of Water
Some plants, like the Water Wisteria and Amazon Sword Plant, can grow both in and out of the water. When purchased in the store, most of these plants will have solid leaves and a firm thick appearance. When planted underwater, an amazing change takes place: the leaves grow much wider and are laced with beautiful flowing clumps.
In Europe, aquarists let these particular plants grow out of the top of the water, and again adjust to open air. They will grow up towards lights hanging one or two feet above the aquarium and revert to their “dry air” form. This presents an interesting look with the “underwater form” of the plant within the aquarium and the “dry season” version of the plant thriving above the tank itself. Though this is not a popular type of aquarium style in the United States and Canada, it is worth a look.
Live aquatic plants belong in home aquariums and the conditions that make aquarium plants grow and thrive make aquarium fish happy and healthy as well. Good basics are all that is needed: proper lighting, substrate, controlled temperature, and healthy water conditions. To some hobbyists, live aquatic plants are as interesting as the fish in the aquarium. And to a select few hobbyists, those who create whole aquacultures and ecosystems for their planted aquariums, the fish are merely the decoration.
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Aquarium Care and Maintenance: Aquatic Plants. Florida Department of Agriculture and Consumer Services