Theres a thread on here bout how long they last in the water. It seems like they last from 5 - 7 years but I'm not 100% sure on tht. The logs will still be there just branches fall apart. Dont put to many in at 1 time.

The people who say I can't do it can just sit the @^#% down and watch me. Friends call me Rusto I also subscribe to pond boss mag. http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=504716#Post504716