Guppy grass (often sold as Najas) is famous in the hobby for a reason: it’s fast, forgiving, and makes guppy tanks easier. It provides instant cover for fry, reduces stress for adults, and soaks up nutrients that would otherwise fuel algae. If you want a planted guppy tank without a complicated setup, guppy grass is one of the safest bets.
Why guppy grass works so well with guppies
- Fry survival: newborn fry can disappear into the tangle immediately. Even in community tanks, that cover boosts survival.
- Calmer adults: guppies feel safer with “escape zones”, which reduces chasing and fin nipping.
- Nutrient sponge: fast growers consume nitrate and excess nutrients, helping the tank stay stable.
How to place it (the easy way)
You don’t need to plant it deeply. Many keepers simply let it float. Floating guppy grass grows quickly, shades the tank slightly, and gives fry a top-level maze near the surface. If you prefer it anchored, tuck a small bunch loosely under a rock or into a corner, but don’t bury it hard — it can rot if packed too tightly.
Lighting and growth expectations
Guppy grass can grow under moderate light, but it will really take off if your lights are strong and your tank has nutrients available. That’s a good problem — it means the plant is outcompeting algae. Keep your photoperiod reasonable (6–8 hours). If you run lights for 10–12 hours, guppy grass may still grow, but algae will try to join the party.
Keeping it tidy without ruining the look
The main “downside” of guppy grass is that it grows fast and can clog filters or block flow if you never trim it. A tidy routine:
- Trim weekly: pull out a handful and cut the longest strands.
- Don’t fear thinning: removing 30–50% is fine. It rebounds quickly.
- Watch filter intakes: a pre-filter sponge helps stop plant bits getting sucked in.
Common mistakes
- Letting it blanket the entire surface: keep an open patch for oxygen exchange and feeding access.
- Over-cleaning it: you don’t need to scrub it; just trim and rinse lightly in old tank water if it traps debris.
If you want a guppy tank that feels “alive” and forgiving, guppy grass is one of the best upgrades you can make. It’s not fancy — it’s effective, and guppies love it.
