Algae in Water

What are Algae?
Algae are unicellular, plant organism, which nourish mainly on the basic nutrients like nitrogen, phosphorus, potassium carbonate, magnesium, lime etc.  They have the ability to assimilate (to absorb CO2 from the air or from the water and to build carbohydrate with the help of sunlight and water), photosynthesis.


They are present in vegetation, in air, on land and in water. Their microscopic small spores are contaminated by wind, dust storm, rain storm and the others constantly in pools and other water tanks. In stagnant waters they grow faster, if they are exposed to sunlight or temperatures above 4 degree Celsius. They can produce unpleasant mucus and/ or odors. In addition, they interfere with the adequate filtration and increase the requirement for chlorination. The existence of phosphate and nitrate in water strengthens its growth.  The algae appear in three main forms: Plankton, filamentous and macrophyta.

Plankton algae are unicellular microscopic small plants that swim freely in water.  If these plants are found in abundance or “flourish”, then it could cause the pond water to become green. Rarely the water adopts a different color because of the algae e.g. yellow, gray, brown or red.


Filamentous algae are sometimes also called as “Thread Algae” or “pond froth”. They appear as fine green threads that form a swimming carpet and often are moved by the wind on the pond. These algae are also often found on rocks, submerged trees and other water plants and boats wharf. 

Macrophyta algae are similar to actual plants, namely in the fact that they appear to have stem and leaves and are attached to land. A Macrophyta alga that is often found is called as Chara or Moschusgras (because of its strong musky type odor). When touched the Chara feels rough because of the lime deposit on its surface. This has further introduced it to one more often used name – Steinwurz.

Algae Problem

Mostly, the algae are of lesser value for its garden pond or lake. The forming of filamentous and the plankton have a tremendous multiplication rate and its sudden death can cause oxygen deficiency. The oxygen required for the fishes in ponds and lakes can be supplied through other water plants in water tanks, which would thrive without having to compete with the algae.

Usually algae problem is caused due to an oversupply of nutrients (Nitrate and Phosphate) in the pond. From the moment a pond is created, nutrients are flown in by the surroundings. The older the pond, more the nutrients are collected and the more susceptible it is for algae problem. The water derived from fertile land, grass land and willows, fodder grounds, disinfection tanks and irrigation lands accelerates the accumulation and growth of algae in the pond.


Excessive algae growth withers or suppresses other forms of water plants; in addition it blocks the sunlight necessary for the normal growth. Taste and smell problems of drinking water and sometimes even the death of fishes are also connected to the excessive growth of plankton. Filamentous and macrophyta algae often build dense plants, which makes swimming and other leisure activities almost impossible for the fishes. An entire covering can obstruct the penetration of sunlight and the production of oxygen and can restrict the nutritional components necessary for better growth of the fish stocks. If the algae surplus comes into conflict with the actual planned usage of the pond, a method should be considered to control the algae.

Algae Control

Carpets of filamentous algae can be removed with a rake, net or similar devices. However these methods of algae control are very labor-intensive and offer control only for specific time limit.  In some cases the algae appear to grow again rapidly just as they were removed.

Before you use chemicals, you should consider the eventual pollution of domestic water supplies and the waiting period for the watering of livestock, the fish consumption, swimming and possible irritations.


A “biological control” arises, if a life form is used to control others or the biological balance is manipulated in such a manner that an unintentional plague is adversely affected.  It would be wise to be very cautious, if one decides on the usage of biological control. Subsequently, it can turn out to be disadvantageous if the life form introduced becomes a bigger problem than the original plague.

“Barley Straw” was tested in England by Center for Water Plants Management for the possibility for control of plankton and filamentous algae.  These tests were carried out continuously for the last 15 years. “Barley Straw” and other types of straws were introduced in the United States occasionally with very mixed results but could not solve the problem completely. 
Types of Algae


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