String algae is a green, hair-like algae that grows on pond rocks, waterfalls, and other submerged surfaces. Excessive string algae growth is often caused by excess nutrients and sunlight.
How to control string algae
- Remove excess algae: Manually remove large clumps using a pond net or soft brush.
- Reduce nutrients: Remove leaves, debris, and uneaten fish food. Avoid overfeeding fish.
- Add beneficial bacteria: Use Aquascape Beneficial Bacteria to help break down organic waste and reduce excess nutrients.
- Add aquatic plants: Water lilies and other aquatic plants provide shade and compete with algae for nutrients.
- Maintain filtration: Keep pond filters clean and maintain proper water circulation.
Aquascape string algae treatments
- EcoBlast® Contact Granular Algaecide (U.S. only): Spot-treats algae on rocks, waterfalls, and other affected surfaces.
- IonGen® System G2 (U.S. only): Helps control string algae by releasing copper ions into pond water. Monitor copper levels according to product instructions.
Always follow product labels and application instructions.
Can string algae be completely eliminated?
A small amount of string algae is normal and beneficial to the pond ecosystem. The goal is to prevent excessive growth rather than eliminate all algae.
Note: UltraKlear® UV Clarifiers help control green water caused by suspended algae but do not control string algae attached to pond surfaces.