Algae Control Guide for Planted Aquariums

Algae growth in planted tanks is a common concern for many aquarists. Correctly identifying the type of algae and addressing its specific cause is the quickest path to a lasting solution.

Main Types of Algae and Their Causes

Green Algae The most common type of algae, attaching to glass surfaces and substrate. Main causes are excessive light and nutrient surplus. It tends to appear when nitrogen and phosphorus levels are high, though small amounts occur even in healthy tanks.

Black Beard Algae (BBA) Attaches like black-to-gray whiskers on driftwood edges and plant leaf margins. Main causes include CO2 deficiency, KH (carbonate hardness) fluctuations, and excessive water flow. It's notoriously difficult to remove.

Cyanobacteria (Blue-Green Algae) A slimy blue-green coating with a distinctive odor. Caused by poor substrate water circulation and accumulation of nitrates and phosphates. It proliferates rapidly in anaerobic conditions.

Brown Algae (Diatoms) A powdery brown algae commonly found in newly set up tanks. It tends to appear when tap water is high in silicates or when beneficial bacteria haven't yet established.

Removal Methods by Type

Treating Green Algae - Reduce lighting to 6-8 hours per day - Increase water change frequency to dilute excess nutrients - Physically remove with a scraper or magnetic algae cleaner

Treating Black Beard Algae - Increase CO2 supplementation to boost plant activity - Adjust water flow direction to avoid direct contact with affected areas - Apply diluted wood vinegar to affected spots (dry treatment outside the tank), then rinse

Treating Cyanobacteria - Improve substrate water circulation (stir the substrate) - Use a blackout (3 days of complete light deprivation) to rapidly reduce numbers - Shrimp and snails are largely ineffective; manual removal is most reliable

Treating Brown Algae - In new tanks, it often subsides naturally, so observe and wait - Remove from glass with a scraper and wait for improved filtration to resolve naturally

Algae-Eating Organisms

| Organism | Effective Against | |----------|------------------| | Amano Shrimp | Thread algae, green algae in general | | Cherry Shrimp | Soft green algae | | Otocinclus | Brown algae and green algae on glass | | Siamese Algae Eater | Black beard algae | | Nerite Snail | Attached algae on glass |

Different organisms target different types of algae, so choose based on the specific algae problem you're dealing with.

Water Quality and Light Management for Prevention

• Keep lighting at 6-8 hours per day, managed with a timer
• Perform weekly water changes of 20-30%
• Avoid excessive fertilization; dose according to plant consumption
• Maintain a balance between CO2 supplementation and aeration

Rather than trying to eliminate algae completely, aim to maintain conditions where plants outcompete algae. When plants are growing vigorously, algae is naturally suppressed.