What is this growth?

[blackandwhite]

Can anyone tell me what this white stuff growing on my driftwood is? I am in the middle of my fishless cycle and the light in my tank is never on, I turned it on tonight just to have s look and noticed his white fuzzy stuff growing in the cracks of my driftwood. How concerned should I be? And can I let it be until it's time to put fish in there? Thanks in advance for your help.

 

[abw0004]

Fungus and looking at the other part of the driftwood you may have BBA starting to grow. What you can do is right before your water change when you normally clean the glass, take a toothbrush (like the free one your dentist gives you) to the wood and lightly scrub like you are brushing your teeth.