Jay - I have that same african wood in my aquariums, it is great!
I think it's like grapevine or mopani wood normally, I just want to tell you that you will want to boil that thing for mb a couple days straight. We are talking about a HUGE amount of tannins in that kind of wood. I boiled my large peice for at least 9 hours, and I still have leeching into my aquarium.
The boiling will also stop the growth of the white fungus that always seems to grow on non-boiled driftwood, it's not harmful, just a bit unsightly.
To reply to that first answer, I thought Jay was talking about the wood invalidating the pH table itself, not just adjusting the pH or acting as a buffer, lol!
Tannins = nice soft water, it just would've been news to me had the wood thrown off the results of the table itself. :lol: