Boom in the Room

You want to make sure such a tripod is stable, certainly when you are extending or turning the center of gravity.
Aside from the weight at the end of the boom I added a special sand bag on the base of the tripod which creates some extra stability.
But what to use when filling a sandbag?
Sand springs to mind ofcourse, but I opted for cat litter.
While te double zipper prevents leakage I minimized this risk by replacing the sand for a larger grain.