Najas Guadalupensis

Najas guadalupensis

Plantae›Tracheophyta›Magnoliopsida›Hydrocharitaceae

📍 Americas

Known as Guppy Grass or Najas Grass, this fast-growing, fine-leaved plant is a superb filtration plant and spawning medium. It floats freely or can be weighted down. Its vigorous growth absorbs excess nutrients, helping combat algae. Very tolerant of a wide range of water conditions.

Tank Mates

Fancy Guppy

Guppy Grass provides ideal spawning medium and fry shelter; guppies thrive in planted tanks

excellent

Red Cherry Shrimp

Shrimp graze on algae and detritus among the plant; dense vegetation offers protection

excellent

Otocinclus

Peaceful algae eaters that won't damage fine-leaved plants; benefit from plant cover

excellent

Neon Tetra

Small, peaceful fish that appreciate dense planting for security and spawning sites

good

Dwarf Hairgrass

Complementary foreground plant; both fast-growing and create layered aquatic habitat

excellent

Bristlenose Pleco

Algae control without damaging delicate plant structure; nocturnal and non-aggressive

good

Common Diseases

Nutrient Deficiency

Symptoms

Yellowing or pale leaves, stunted growth, leaf holes or transparent patches

Treatment

Dose liquid fertilizers containing macronutrients (NPK) and micronutrients (iron, trace elements) weekly; increase water change frequency

Algae Overgrowth on Plant

Symptoms

Green, brown, or black algae coating plant surfaces; reduced light penetration

Treatment

Increase plant density to outcompete algae; reduce light duration to 8-10 hours daily; add algae-eating fish like Otocinclus or shrimp

Decay and Melting

Symptoms

Plant tissue becomes mushy, discolored, or dissolves; foul odor from decaying matter

Treatment

Remove affected portions immediately; improve water circulation with aeration; reduce organic buildup through more frequent water changes

Poor Growth or Stagnation

Symptoms

Minimal new growth, pale coloration, plant appears dormant despite adequate light

Treatment

Check water parameters (pH 6.0–8.5, hardness 2–20 dGH); ensure temperature is 18–28°C; verify adequate lighting (low to high); dose fertilizers if nutrients are depleted