Suggestions for filling speakers stands?

I have experimented with much of what is listed here as fill material. I agree with Sdcampbell about the lead and sand combo, I use it in the tubular housings of my Soundlab U-1's. Silica turned out to be best for my aluminum turntable and phono stands. This is the material used for sand blasting. It's extra clean, and free of contaminants, bone dry, reasonable weighty, has sharp edges that packs like crystal inside the stand. Non toxic with normal handling, a 25 pound bag cost $21.00.

A word of caution when filling with playground sand or other gritty materials. If your stand has spikes exiting the bottom, be certain the threads are isolated from the compartment you are filling. Failure to do so will allow grit to fill the void as adjustment is made. The spike finally freezes up and cannot be turned without damage to the adjustment threads or the stand itself.

For completely different approach, use vibrapods between
speaker and stand you will be amazed at the difference in sound. You will get deeper bass which is the major shortcoming of small 2 way speakers. Very cheap tweak to try, and stands then don't need to be filled. Overall sound in most cases will be improved.

Don't dismiss this tweak without trying it first!

I know there is someone who sells silicone in audio form, but i have forgotten who they are. The only other place i can think of is a pool table/bar-games store. Some of these stores sell those long wooden tables where you try to slide a puck in to a defined area for points, like shuffleboard. These tables use silicon sand for the puck to slide over, and of course the store carries the 'sand' ( in a very fine form). Looks like Albert has found a less expensive sorce, though, there's no way you're gonna get a 25lb bag for $21 at these stores. I use the word 'silicone' meaning a "solid", but i am not sure whether that variation of the base word specifically refers to the more liquid form instead. I'm not absolutely positive, but silicon probably has the one of, if not the highest, energy-transfer/density ratios of the materials used by audiophiles. If i do think of that audio company, i will let you know.

I believe it was Target that offered Silicon for filling audio stands, but I am not certain if they are still in business.