Species Catalogue

Creeping runners bearing upright branches tipped with small spherical beads — resembling tiny bunches of grapes. One of the most vigorous nutrient-exporting macroalgae; grows rapidly in refugia. Can go sexual and crash if left unharvested for too long. Listed as invasive in the Mediterranean.

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.