Might try reducing light to four hour's for now,increase CO2, start with some type of fert routine whether it be EI or other.
With light and CO2,plant's will be hollering for fertz which may or may not be sufficient with contribution from the aquasoil alone.
Agree with removing what algae you see, +water changes.
Can alway's increase light when plant' start responding more favorably.
Just my two cent's.
Fertz will assure that plant's have what they need for growth.(along with light,CO2)
When plant's are thriving,algae has harder time.
If plant's are lacking in food,CO2,then algae which need's much less of everthing can thrive.
Big water changes,remove algae you can,feed the plant's.
From photo's, it look's to me like you could gently push the root's that are near the surface a little deeper with finger's,eraser end of pencil,chopstick,or some other tool that does not tear the root's.