Clear the algae from the surface of the lake or pond. Use an algae rake to collect the algae, as this will help to remove the strands that attach the algae to the deeper strands. Repeat this process regularly during the treatment phase to speed up the removal of the algae, especially as they begin to die. Also clear away leaves and other organic matter from the surface of the lake, as these provide nutrients for algae growth.
Reduce the number of fish in the lake, because the nitrogen produced will feed the algae. Either begin culling the fish, or limit the introduction of new ones. Keep animals such as ducks or any other livestock away from the lake. This process will have a major impact on the algae levels.
Leave a 10-foot strip around the lake unmown. This process will help absorb any runoff from fertilizers, which will prevent the algae from accessing nitrates that help it to grow. Ensure that any septic tanks are separate from the lake, as this will also provide nutrients for algae growth.
Place a bale of barley straw in the lake in the sunlight. As the barley straw decomposes, it will produce a chemical that will begin to kill the algae. This technique will only work in combination with regular raking. Place five bales per acre of lake.
Use algaecides if the lake is within private land. However, if your lake is publicly owned, is frequented by swimmers or used by livestock, you will be unable to use algaecides, as these can cause serious harm. Use sodium carbonate peroxyhydrate products that inhibit the growth of the algae if the barley straw does not work. Check your state's environmental restrictions before using this treatment.