Rotala
Genus of stem plants with colours ranging from green to deep red. The most demanding species are among the most beautiful of planted freshwater.
Detailed explanation
R. rotundifolia is the easiest: green in low light, reddish in bright light and CO2. R. macrandra is among the most beautiful and demanding: intense red but requires very strong light, CO2 and precise fertilisation.
A. H'Ra is a popular variety with orange-red colours accessible even without extreme conditions. R. indica is easy and versatile.
Rotalas are pruned by cutting the tops and replanting them. The lignified bases are discarded. Growth is rapid with CO2.
The red colour depends on: intense light, abundant iron, low nitrates (the plant produces red pigments as protection from excess light).