White Fungus Circles On Wood

[FungusTrooper]

Hey y'all,
 
We have a tank that contains a single male golden gourami, and it's been established for a few weeks now. Planted, etc. Less than a week ago we put a piece of manzanita wood from a LFS that we'd soaked for a few weeks and removed as much of the tannin as possible. I tied a few java ferns to it and popped it into the tank.
 
Day before yesterday I also dosed with Tetra Blackwater Extract. Correct dosage as per the bottle.
 
Yesterday evening, we noticed some fungal growths on the wood which we haven't noticed anywhere in any of our tanks so far. Can anyone ID this, and say if it's harmful or something we don't need to worry about?
 

 

 
Thanks.

 

[Blondielovesfish]

Looks like some sort of mold. Not sure what type though. Probably not harmful.

 

[Blondielovesfish]

Further reading indicates it may sap. It's common on Mopani wood, though I'm not sure about Manzanita.

 

[Zikofski]

all i shall say is if you are worried take it out give it a good scrub under some tap water then put it back in with a water change