Flora & Fauna

Not a true alga but a charophyte — an evolutionary stepping stone between algae and land plants. Whorled branches on brittle stems; produces a distinctive musky smell when crushed. Tolerates very hard, alkaline water that many plants cannot. Often kept deliberately in biotope setups for its unique look.

Fine, powdery green coating on the glass that wipes off easily but returns quickly. Different from Green Spot Algae — much softer and more responsive to physical removal. A large clean-up crew (nerites, Mystery snails, Otocinclus) keeps it in check. Usually a sign of moderate light excess.

Hard, dark green circles on glass and slow-growing plant leaves — familiar to virtually every planted tank keeper. Caused by low phosphate (counterintuitively) and high light. Nerite snails are the most effective control. A small amount is considered normal and harmless.

Pea-soup green tank water caused by a bloom of free-floating unicellular algae. Usually triggered by a combination of high nutrients and direct sunlight. A UV steriliser will clear it within days. A 3-day blackout is an alternative. Daphnia (water fleas) can be added to a fishless tank as biological control.

Fine, bright-green strands that drape over plants and hardscape. One of the most common new-tank algae — usually caused by excess light, nutrient imbalance, or lack of fast-growing plants competing for nutrients. Nerite snails, Amano shrimp, and Florida Flagfish make short work of it.

Thin, cotton-like green threads that form loose, easily detached clumps — often confused with hair algae but coarser and more tangled. Tends to form clumps rather than sheets. Usually caused by excess ammonia or organics in new tanks. Amano shrimp and Florida Flagfish handle it well.

Very fine, dark green threads — slightly stiffer than Spirogyra and less silky. Wraps tightly around plant stems and mosses. Caused by low CO₂ and high light. Siamese Algae Eaters are one of the few fish that readily consume it.