the Ph problem stems from the wood releasing tanins into the water. Depending on where you are getting your wood, this may not be an issue. Do a little test first: put the wood in a bucket of water for a few days before adding it to the tank. if the water turns brownish, it still has tanins in it, and t will raise your pH over time. Regular water changes usually offset this. If the water is a really dark brown, continue to soak the wood, changing the water in the bucket every few days, until the water stays clear (or nearly so) for a few days. One note of caution: some stores sell grapevine wood for use with reptiles. This stuff is not suitable for any aquatic environment. It leeches an oily substance into the water which never seems to go away. It's still great for reptiles though.