hi guys, aprox 2 weeks ago I picked up a great pc of wood-Mylasian? Not Mopani, this wood is on the soft side ,can scrape with fingernail. So I have been boiling daily to get most of the tannins out , just want to leave a little. The water has been tea-color as usual, but yesterday and today I noticed some bubbles in the water. I have checked with everone in the house to make sure nobody touched it (it iis half sticking out of the water ,and I need to keep turning it) ,noone had touched it ,I made sure no hand cream ,no soap residue when i turn it..so wonder where the bubbles are coming from all the sudden. Any ideas ? I dont feel it will be safe to use when the tank is ready for it ,unless others have seen this also. I have always boiled my wood ,different kinds and never saw this before and it didnt happen the first 2 weeks of boiling , just started yesterday and today. Ideas what is up ? thanks