Potamogeton gayi

Potamogeton gayi is native to slow streams and ponds in South America and is one of the more aquarium-suitable Potamogeton species. Its leaves are extremely narrow — almost thread-like — and arrange alternately along branching stems, creating a fine, billowing texture that responds beautifully to water movement. Under good light it grows at a moderate pace and provides excellent cover for fish, making it a practical as well as visually pleasing background choice for South American biotope aquariums.

Light: Medium (35–55 PAR); benefits from consistent light to maintain steady stem growth. CO2: Beneficial; injection improves vigour and stem density. Planting: Plant stems in groups of 5–8 in the background; remove lower leaves before planting to prevent rot. Maintenance: Trim tops when stems approach the water surface; replant healthy cuttings for denser groups. Note: Fine leaves can trap debris — gentle flow over the planting helps keep the foliage clean.