One of the hardest things to control in a pond is algae growth. There are many different products on the market and most of them are effective in certain situations, but there are advantages and disadvantages to all of them. To cut through all of the hype it is important to understand exactly what algae is and how each different product works to control it.
Algae is a natural and important aspect of a water garden, however, if the eco-system is not well balanced it can be a major problem. In a garden pond there are three main types of algae; green water, string algae, smooth coating. Sludge is not actually living algae, but it is another cause of dirty water in a pond.
Algae is the simplest and one of the oldest forms of plant life. There are hundreds of thousands of different varieties. No one knows an exact number and more are being discovered all the time. Algae blooms in the oceans can be so immense that they can be seen from space. It is estimated that 40% of oxygen in the atmosphere is produced from this type of plant. Being near the bottom of the food chain algae is vital to many eco systems around the world, although it can be a very big nuisance in the water garden! It can take many different forms. Algae can grow in sheets known as string algae or it can grow as a smooth coating on all surfaces. The most common form is free-floating particles that give a pond a green tinge.
Sludge is another source of dirty water. When plant life dies, the rotting remains turn into a layer of thick sludge on the bottom of the pond. It is impossible to prevent this completely, but there are a number of things you can do to keep it under control.