Here is one prior thread on gravel for BG beds. 8 - 32 mm is optimum as per this source for BG beds.

http://www.pondboss.com/forums/ubbthreads.php?ubb=showflat&Number=7630&fpart=1

Here is another one on BG spawning.

http://www.pondboss.com/forums/ubbthread...ite_id=1#import

Last edited by ewest; 06/01/09 08:58 AM.