How to Keep Marine Algae
- 1). Place the aquarium near a window that gets 12 to 14 hours of sunlight everyday, or install a natural sunlight bulb to bring the total amount of exposure up to this amount. Sunlight or simulated sunlight encourages algae to grow.
- 2). Change a quarter of the water regularly. Keeping the water fresh provides a steady supply of nutrients and cleans the tank of excess waste. The fresher and cleaner the water, the better the algae grows. Avoid siphoning any area where stringy algae is growing.
- 3). Reduce the level of carbon dioxide in the water. This can be done by raising the water temperature. Keep the temperature toward the upper end of a range comfortable for the fish and do not add extra carbon dioxide to the tank.
- 4). Remove any coral or live rock from the tank. These naturally compete with algae for nutrients in the water. Eliminating the competition encourages algae to grow.
Source...