Who Gives A Fish Forums

Never had biofilm, but my tank's heavily planted. Maybe add some floaters? They soak up excess nutrients and reduce surface scum.

Mine did this when the filter flow was too high. They seemed stressed. Lowered the flow on my canister, and they calmed down. Maybe check if your FX6 is too strong for them.

Anubias grows slower, which is nice if you don't wanna trim often. Buce can take off if it's happy, but like everyone said, it's a gamble in low tech.