I used sand on my Skylan stands ( 20" high 4 post ) filled aprox 2/3..I used construction sand ( in tubular bags )...Its a larger sized sand and works great..The real trick is to not over fill...You can over do it..I found 60-70% worked best for me...You can try 50% and always ad more if you need to......I also found that using the Big Fat Dots ( or similar ) for transition between stand and speakers works well...
