Today I have some random bought plants for my 500l it’s currently lightly planted but has lots of artificial and I’m in the process of going all natural , I currently have 5 Amazon swords and 5 Marimo moss balls , today I’m introducing hornwort , Java fern and yes more Marimo moss , Iv heard good things about hornwort a very beneficial plant , question being as a floating plant will the reduced movement of the water surface from the plant effect oxygen or will the plant replace the lost oxygen