Why Aquarium Plants Die: Light, CO2, and Species Selection

Your Plants May Not Be True Aquatics

Hygrophila (likely H. polysperma or similar) and "green hedge" (possibly Alternanthera or a terrestrial hedge plant) are often sold as aquarium plants but **grow best emersed** (leaves above water). Submerged, they often melt, turn brown, and rot unless given intense light and CO2.

Requirements for Demanding Plants

• Light: 50+ PAR at substrate (high-end LED or metal halide). Standard fluorescent is insufficient.
• CO2: Pressurized system at 20–30 ppm, not a DIY yeast reactor.
• Nutrients: Complete liquid fertilizer (macros + micros) + root tabs for heavy root feeders.
• Substrate: Aquasoil or enriched gravel, not plain sand.

Better Choices for Low-Tech Tanks

• Anubias, Java fern, Cryptocoryne (low light, no CO2 needed)
• Vallisneria, Sagittaria (moderate light, root feeders)
• Floating plants: Salvinia, Frogbit (shade tank, absorb nitrates)

Match plants to your setup. If you can't upgrade light/CO2, choose undemanding species. Your fish will thank you for the stable water quality.