• Elodea is an attractive plant in home aquariums.Aquarium image by crossgolfing from Fotolia.com
  
  Elodea is a fresh water plant commonly used in aquariums. Some species are native to North America and are important parts of aquatic ecosystems. It can grow quite prolifically and has inadvertently become a noxious weed in some waterways of the world. Elodea provides food and shelter for macroinvertebrates. When it dies, the plant is broken down by bacteria and fungi.
  
  Educators frequently use elodea in ecology experiments. The plants have thin leaves, which make them ideal for looking at live plant cell structure under a microscope.
  
  

Nutrients

• Manure washes into streams and increases the nutrient levels.cows in a field image by redrex from Fotolia.com
  
  Elodea grows best in water with high nutrient content. This is a frequent situation in aquariums. In a natural ecosystem, land uses in the watershed will affect the nutrient levels in streams and rivers. Any kind of use that requires the addition of fertilizers (e.g., crop land, manicured lawns, golf courses) or concentrates the number of animals (feedlots or small, isolated wildlife areas) will likely mean nutrients are seasonally elevated. Rain washes the nutrients right into the streams.
  
  Elodea, other aquatic plants, and algaes, will grow unfettered by natural nutrient limits. "Blooms" can occur in aquariums as well as natural ecosystems. Once the surplus nutrients have been depleted, the elodea rapidly begins to die off.
  
  

Light

• Plants need light to grow.lillies in sunlight image by Al T from Fotolia.com
  
  Elodea is a plant, therefore it must have sufficient light to create food through photosynthesis. In a small space such as an aquarium, excess light will spur growth and plants will grow unfettered. In a natural ecosystem, sunlight is available for a finite amount of time each day and therefore can somewhat limit growth rates. The depth the sunlight can penetrate will limit how densely the plants can grow. However, given unlimited space, the elodea and other aquatic plants and algae will spread across the surface of the water.
  
  

Temperature and Oxygen

• Water that is too cold cannot sustain plant life.river current among a snow. a winter landscape. image by Sergey Ilin from Fotolia.com
  
  Elodea and other aquatic plants grow best in moderate temperatures that allow for optimum cell function. Water temperature also controls the amount of oxygen available for photosynthesis. While the photosynthesis creates a net output of oxygen, a small amount of oxygen is needed. Water that is too warm will not have sufficient levels of oxygen for photosynthesis to occur. Water that is too cold will slow reactions to the point that not enough photosynthesis can occur each day to sustain the plant.