I pulled it from the tank and put it in the laundry tub, cranked up the water heater to wow thats hot
added some bleach, and went to town with a wire brush, & lots of wood came off.
Drained the water and refilled twice ,& going to let it sit for a while, & add some prime later today.
And if the funk comes back,,,
Ph here is about 7.8
"it was not sandblasted enough (good for reptiles, bad for fish)",,,,,I think you hit the nail on the head
"you need to keep a Pleco in your tank to help maintain the wood surface",,,,,Good idea, I had one a while back and it was always on the wood.