I have a relatively new West African Killifish/ADF tank with (what used to be) a large assortment of small Anubias variants. Over the past month or so, one by one they have been succumbing suddenly to rhizome rot. Each one maintains perfectly green leaves but the rhizomes are reduced to a mush with an absolutely hellish odor. Before anyone says the standard "don't bury them" none of these have been buried, be it their roots or rhizome. All have been lightly wedged into nooks and crannies in driftwood and lava rocks to allow the roots to attach to the surface. The only commonality that I have noticed so far is that all of the ones that have succumbed so far exhibit a white fuzz around the rhizome, which I assume is the same Saprolegnia mould which has been on my mopani driftwood since day 1 of having the tank filled with water (and throughout the cycling process, to now post-cycle and fully set up). I am becoming increasingly worried over the Saprolegnia as it has not gone away on its own as so many threads I've read advise and it seems to spread to any Anubias which comes into contact with it. Does anyone know if Saprolegnia actively attacks Anubias rather than only establishing on necrotic tissue? If it is indeed the Saprolegnia that is devastating my Anubias, how can I keep it in check?