What to fill Skylan stands with for Harbeth SHL5s


Skylan stands for SHL5s: could someone please tell me what to fill them with?
Skylan advised PURINA MAXX kitty litter, but I cannot find this in the U.S.
Should I use play sand, sand kitty litter, clay kitty litter, something else?
Thank you.
rgs92
Skylan stands are awesome.

Noel is the nicest guy and really knows his stuff about good sound.

He taught me more in a half hour that I did not know for years !
Silica sand - THE END. Get yourself some through a janitorial firm (silica sand was always used for public high volume ashtrays). Noel is a genuine guy and his product typifies beauty in simplicity.

Coincidentally, I just the other day listed one of Skylan's audio racks for sale on a couple of different (free) sites, and have been absolutely inundated by interest. I own 2 rack models and 2 sets of speaker stands, one pair of which were configured in the mid-80's, and just so good, I've never been able to let them go - despite owning only planars for the past 6 years. (you never know when I might need those stands again!). They're a load to move around because they're full of silica sand - solid and dead as can be - not sure why you'd use anything else. Hats off to Noel and his excellent, simple products!
My wife has acquired a taste for Native Indian pottery. She decorated an area in the music room with the expensive vessels. They had a tendency to hum along with the music, but after filling them with sand (2 dollars for 60 lbs at Home Depot), they actually make the acoustics of the room better by removing an echo...they are absolutely DEAD when tapped.
I'm using 24", two-post Skylan stands under a pair of EOS HD monitors. I found Noel's stands to be a bargain, well-designed, rigid and non-resonant when filled with a combination of lead shot and washed playground sand. I used 6 lbs of #9 lead shot mixed with about 14 lbs. of sand in each post. (About 40 lbs./stand) The lead shot is mixed with the sand from the bottom to middle of the post; sand only from the middle to top. While the results are quite good, I'm going to add more shot and sand and have a listen to see if the added weight makes a sonic difference. I also use 4 Herbies Audio Labs Square Fat Dots under each speaker. These are specially formulated for loudspeaker decoupling and are quite effective. They will tame floor resonance, tighten the bass, and allow more detail to be revealed in the music. One Harbeth SHLBs owner who uses the Fat Dots claimed "the sound opened up considerably."