Guppy Grass - The Prolific, Oxygenating Nursery Grass... Guppy Grass (Najas guadalupensis) is one of the most efficient, fast-growing, and versatile aquatic plants in the aquarium hobby. Renowned for its delicate, branching stems and narrow green foliage, it is famous for its ability to form dense floating or planted tangles. It acts as an incredible natural water purifier and provides unmatched sanctuary for newborn fish, making it an essential staple for breeders and community tank keepers alike. Key Features Incredible Nutrient Sponge: Fast-growing stems aggressively pull nitrates, nitrites, and excess phosphates directly from the water column, significantly suppressing algae growth and keeping water parameters stable. Ultimate Fry & Shrimp Nursery: Forms intricate, dense biological thickets where tiny fry (like guppy, molly, or platy fry) and baby shrimp can safely hide, forage, and evade larger tank mates. Dual Planting Flexibility: Can be planted directly into the substrate or simply left floating on the surface to form a natural, shade-providing canopy. High Oxygen Production: Rapidly oxygenates the water column, creating an invigorating environment that benefits both fish and beneficial bio-filter bacteria. Practical Usages Livebearer & Breeding Setups: An absolute must-have plant for tanks dedicated to guppies, endlers, killifish, and livebearers to maximize fry survival without requiring separate nursery boxes. Shrimp Habitats: Provides ample surface area for natural biofilm growth, serving as an active feeding zone for dwarf shrimp species. New Tank Stabilization: Ideal for cycling new aquariums or stabilizing tanks experiencing sudden nutrient spikes. Planted Setup Integration: Pairs exceptionally well with biological filtration systems (such as air-pump driven sponge filters) to maintain a pristine, low-stress aquatic habitat. Dos and Don'ts Dos: Do let it float freely if you want to provide upper-level cover and shade for light-sensitive fish or top-dwelling species. Do trim and thin out the mass regularly using hands or scissors; it propagates rapidly from simple stem cuttings. Do ensure gentle to moderate water movement so the floating tangles don't trap excessive particulate waste. Don'ts: Don't handle the stems too roughly; the stems are naturally delicate and brittle, though broken fragments will easily grow into new individual plants. Don't bury large, deep clumps tightly under coarse gravel, as buried stems deprived of light may decompose. Don't let it overgrow and completely choke out light from reaching slower-growing bottom plants like Java Moss. Care and Growth Guide Lighting Requirements: Low to High (thrives in almost any lighting condition). Growth Rate: Extremely Fast. Placement: Floating or Background (stem plant). Temperature Range: 18°C to 28°C (64°F to 82°F). pH Level: 6.0 to 8.0. CO2 Injection: Not required; thrives easily in low-tech environments.