hi,
the one on the left looks like Cabomba Caroliniana the other on looks like Echinodorus Bleheri. tbh they are both easy to keep no need for a CO2 unit. a bit of info on them,
Cabomba Caroliniana
This plant is easy to keep, although out of water it travels badly.
It has a high Alleopathic factor, which may be useful in keeping algae at bay, but also can be an adverse factor to certain other plants.
Like many Aquarium Plants strong water circulation is important, as it will easily become slimy in still water. The temperature should be kept at the lower end of the range for best results.
Maintenance Class : This plant is classed as fairly easy to care for.
Tank Position : This plant is recommended for a background planting position.
This Plant Is Suited To The Following:
• A pH range between 6.0 and 7.2.
• Soft to Hard water attributes.
• Temperatures between 64° and 79° Fahrenheit (18° to 26° Celsius).
• High intensity lighting.
Echinodorus Bleheri
This plant is commonly known as Amazon Sword Originates from S. America.
Without any doubt the most popular Aquarium Plants of the large Echinodorus family, and deservedly so. The leaf colours can vary from a dark green, to a lime green shade.
It grows fast, and should be pruned periodically. Reproduction is by runners, which when they show small plantlets, can be cut and placed into the substrate to become a new plant.
Is very tolerant of a wide range of conditions. It is subject to a bacteria, that can cause the leaves to become pale brown and translucent.
If this occurs one should try a short dip in a 1% Permanganate solution, and if this does not quickly show improvement (2-3 days), then the plants should be discarded.
Over all though a highly recommended plant for mid to background decoration.
Maintenance Class : This plant is classed as fairly easy to care for.
Tank Position : This plant is recommended for a middleground / background planting position.
This Plant Is Suited To The Following:
• A pH range between 5.5 and 9.0.
• Soft to Hard water attributes.
• Temperatures between 68° and 86° Fahrenheit (20° to 30° Celsius).
• Medium to High intensity lighting.
hope this help jon