In What Conditions of Water Does Algae Grow?

When you discover algae growing in your pool, drinking water or fish tank, it's important to understand why that algae is growing there. Knowing what water conditions support algae growth can help you to keep your water clean. On the other hand, if you're trying to grow an algae colony to support particular fish, knowing what conditions algae thrives in can also be beneficial.

  1. Temperature

    • Algae require a water temperature between about 60 and 80 degrees Fahrenheit. Temperatures lower or higher than this will either stop algae growth or kill the colony.

    Stable pH Levels

    • Algae needs a pH between 7 and 9, and grow best in the 8 pH range. Water with a lot of organic waste matter in it can contribute to higher pH levels, essentially feeding the algae.

    Under-Planted Areas

    • Algae does well in water areas where there are no other plants to compete with for nutrients. Water that has many other plants may not grow algae as readily.

    Aerated Water

    • Like all plant life, algae need a steady flow of air in order to achieve photosynthesis. Water that is well aerated or flowing gently also helps to expose all the pieces of the algae to light and any nutrients that may be in the water. However, too much aeration can kill algae.