Hi,
in the bottom picture, the plant on the left should likely be 'Hydrilla' (Egeria Densa) and in the centre, Hygrophilla Difformis.
Both are ok with no co2 injection, but need adequate amount of light to do well.
Correct me if i'm wrong.
You may also like to check out this page. www.tropica.com to find out more on the requirements of the plants.
Cheers!
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