Im itching to get my new 90gal tank up and running, but I cant due to financial problems. I was thinking about taking a walk through a random forest in hopes of finding a creek or small river and possibly finding some driftwood. If I do actually find some driftwood are there some types of wood that will be poisonous to the fish? Off the top of my head I would guess birchtree wood would be a no no as it contains alot of chemicals. Any others I should watch out for and what are some wood types that would be ok to use?