Red aquarium plants

Red is a stress color, and most plants on this page only show strong red when the tank pushes them. A few, such as the cryptocoryne wendtii red, hold some red in modest light. Light comes first: most of these stems list high light and stay green under less. CO2 keeps the growth compact and the color holding. The easy plants manage without it, but the Ludwigia Pantanal and most rotalas do not. The Rotala H'ra and Rotala Orange Juice list CO2 as beneficial. Iron and the other micronutrients build the pigment, so a red tank gets dosed. And many rotalas and ludwigias redden hardest when nitrate runs lean, which is the one lever that costs nothing.

1. 01

   Light makes red

   Most of these plants stay green under low light

2. 02

   CO2 holds it

   The easy reds manage without, most rotalas do not

3. 03

   Iron in the mix

   Red pigment needs iron and micronutrients

4. 04

   Lean nitrate

   Many rotalas redden when nitrate runs low

The Rotala H'ra and Rotala Orange Juice are both marked medium at 11.8 inches (30 cm), with high light and CO2 beneficial. The Rotala H'ra needs high light to color, and at that light CO2 becomes effectively necessary to stay ahead of algae. The rotala macrandra is marked difficult, 19.7 inches (50 cm) of scarlet that needs high light, steady CO2 and soft water. The Rotala Blood Red is a background stem that reverts to green and stretches in low light. The rotala wallichii is the fine-leaved one at 11.8 inches (30 cm), marked difficult. The Ammannia gracilis is marked medium, a fast 19.7 inch (50 cm) stem that goes orange-red under high light, and the Ammannia Bonsai is its slow, compact cousin at 7.9 inches (20 cm).

The ludwigia palustris is marked easy in medium light, a fast 19.7 inch (50 cm) stem. The Ludwigia Rubin is the same rating with broader, darker red leaves. The ludwigia brevipes is marked easy but lists high light, a narrow-leaved stem for the midground at 11.8 inches (30 cm). The ludwigia arcuata is marked medium with needle leaves that turn orange-red in high light. The ludwigia glandulosa is marked difficult, slow and deep red at 15.7 inches (40 cm), and it needs CO2 to hold. The Ludwigia Pantanal is marked difficult for high light, CO2 and very soft water, and the Ludwigia Cuba carries the same ratings.

The alternanthera reineckii is marked medium for medium light, a 19.7 inch (50 cm) stem with red-purple leaves that stays more compact under high light. The Alternanthera reineckii Mini is the foreground form at 3.9 inches (10 cm), marked medium for medium light, and the closest thing to a red carpet. The Alternanthera Rosanervig has pink leaves with pale veins. The Aflame sword is a slow sword marked medium for high light, 11.8 inches (30 cm) of red-brown leaves. The red water lily is a bulb marked easy that grows fast to 23.6 inches (60 cm). The dwarf aquarium lily and the micrantha lily are the small ones at 9.8 inches (25 cm), both marked easy. The dwarf aquarium lily has red-brown leaves that float if you let them.

The red cabomba is marked difficult, a 19.7 inch (50 cm) stem for warm, soft, acidic water. It wants 75 to 82°F (24 to 28°C) and very high light. The Nesaea crassicaulis colors up only under bright, unobstructed light with CO2, at 19.7 inches (50 cm). The Nesaea pedicellata Golden is the yellow-gold one on orange-red stems. The Ammannia senegalensis is copper and red under intense light and dull green in shade. The mermaid weed is marked medium, a feathery 11.8 inch (30 cm) stem that turns orange-red at the tips under high light. The Hadi Red Pearl sword is marked easy, a compact sword at 9.8 inches (25 cm) with red-speckled leaves.