Why do aquatic plants have few root hairs?

The bulk of aquatic plants is algae. In principle, they have no roots, since they are lower plants. In principle, they do not need roots. They have plant parts that are fixed at the bottom of the reservoir. The root is necessary for the plant to absorb water and minerals from the soil. Since water is everywhere in the aquatic environment, a specific organ is not required to absorb it. Algae absorb water over the entire surface. They also receive minerals. Only some of the more complex plants in the water have root hairs.