2Hr Aquarist Commentary: Alternanthera reneckii (AR) comes in different varietals, with the AR "mini" gaining popularity these days because it is shorter and redder than the other varietals. The 'mini' varietal is a good foreground/midground plant, while taller varietals such as the 'rosaefolia' are suitable for backgrounds in a planted aquarium. Detailed guide here. AR can grow without injected CO2, but the coloration would not be as rich and the overall form would not be dense / compact.
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