Is it safe to use these 2 pieces of driftwood in my aquarium? I found them at Wichita Falls about 5 years ago. They have just been sitting in a box since. I'd do a bleach soak for several days, then a fresh water soak for several more, changing out the water daily. My concerns: I don't know what type of wood it is other than hardwood. I read that walnut should be avoided. Since they were harvested from a river, should I worry that they may have dangerous chemicals inside that would kill my fish? Also, I have mystery snails, however my PH is 8, and I'd like to do a community tank so wouldn't mind if the driftwood brought it down slightly, I think?