My tank is currently cycling (fishless) and I have just noticed loads of white coloured fluff/mould growing on my piece of bogwood. Is this algae? Is it harmless?
In my experience and others I've spoken to this is due to sap still being present in the wood. Remove the wood from the tank, scrub it clean and dry the piece out for a few days in the airing cupboard, afterwards put it back and chances are it won't reappear. If it does just repeat the process until it's gone.