I recently planted an Anubias Nana in my tank. I placed my Marimo close to it, I really liked the look of it. However I'm wondering if this is wise placement. Will this encourage algae or mold grow on the Anubias? The plants look good right now, but they haven't been together long.
While you can plant Anubias into the substrate, it is a rhimzone plant. This means it thrives when it is attached to wood or rock so the roots grow onto it, instead of into the substrate. This also applies to Java Ferns. I’m at my desk so I’ll show my example Those 5 plants on the wood are all Ferns/Anubias, attached to my driftwood.
The rhizome will rot if it is under the substrate and then the plant will die. You "can" do it but you will have to constantly check after water changes etc to make sure it is not. The rhizome is the thick ball knot that the roots come out of.
I always plant my anubias in the substrate but as other noted the rhizome should be off the substrate. Back to the original question - i've not noticed my moss balls causing algae to form on my anubias. To be honest in the year i've had them they haven't done much (either good or bad - they just sit there mostly clean 'cept the one in the krib tank where the krib insist on adding some substrate on top of it once or twice a week. Then it gets substrate on it till i do a water change and roll it over Them kribs are almost as bad as my jungle val.