They are able to do this because of their unique root systems. The nutrient in the water, occurs naturally, through added water, dust, fish waste, uneaten food, decaying plant parts etc. Oxgenators Submerged plants, often called oxygenating plants, grow submerged beneath the pool's surface. Their primary function in a water garden is to take up nutrients, thus helping to control algae . They add oxygen to the water and serve as a filter by absorbing dissolved nutrients and competing with the algae.
Oxygenating plants are essential for pools with fish.
Not only do they help establish a natural balance in the pool, they also serve as a food source, spawning mats, and a hiding place for baby fish.