Algae Control in a Small, Full-Sun Pond: Saving Plants and Fish

A 125-gallon preformed pond in full Georgia sun struggles with algae, while plants yellow and die. Fish are healthy. The fix: reduce light, boost plant competition, and ensure proper planting.

Why Plants Fail

• Full sun + small volume = overheated water, stressed roots.
• Planting in pots with inadequate soil/fertilizer.
• Goldfish nibbling tender growth.

Action Plan

1. Shade 40–60% of the surface with a shade sail, floating island, or additional floaters.
2. Repot plants in clay-based aquatic soil topped with pea gravel. Add fertilizer tabs.
3. Choose sun-tolerant varieties: Hardy lilies (e.g., 'Attraction', 'Comanche'), dwarf cattail, pickerel rush, water hibiscus.
4. Upgrade filtration: Add a small bog filter or increase bio-media.
5. Barley straw extract or pond peat in the filter for ongoing algae suppression.

Small ponds in full sun are algae incubators. Shade and vigorous plants are your best allies.