Lupin, is there something wrong with using fruit tree wood? I have been using a branch that I removed from an apple tree in my back yard. It was a branch that had died a year before and I just cut the dried branch, boiled it and put it in my endlers tank. It is good solid intact wood that is doing very well and seems to be having no problems. I know it has never been sprayed because I don't spray my apples. I always thought of it as a superior wood because it is so tight grained compared to most any other wood. It is a very hard wood, not at all like grape vine.