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
Thanks everyone. Sure is a multitude of opinions here!
I haven't set them up yet (no stands yet), but I'll report soon.
Quick comments on SHL5s (2007 30th anniversary edition with upgrade OFC internal wiring) on the floor...
Outstanding overall speaker. No offending characteristics.
No longer have to segregate my CDs based on how listenable they are--all are musical. Very nice vocals. Not state-of-the-art imaging in any direction but still has images in a nice 3D space with natural size sounds. A nice balance between fullness and image-boundary conditions. Reminds me very much of Sennheiser 650s (with a great headphone amp) but with better definition and detail. Silky and not abrasive at all. No screeching, grain, or hash or buzziness. Bass is solid and full but not boomy, a bit muddy on the floor, but really excellent on temporary tables I tried for a while. Overall, not nearly as tonally or spatially detailed as former Kharma 3.2s or Wilson WP6s,
but none of the pain from overexposure either that led me away from these. More transparent and better soundstaging than former Aerial 10Ts I had, without the occasional overrought bass or rare piercing lower treble. But, like Aerials, I can sit for long periods with zero fatigue.
Very balanced sound from top to bottom. Deep bass or sparkling highs only hinted at, but enough to be satisfying.

Sounds better with my single-wire Cardas Golden Ref speaker cable on the upper posts, despite Harbeths recommendations. Sounds better using EMM DCC2-SE's preamp
rather than separate preamps I have (Mac C46 or Jeff Rowland Capri). I use Stelth Indra ICs for all. (Actually, only one pair used for DCC2 to Edge NL12.1 amp.) I also use a Hydra 8 to plug in sources, and plug the amp right into the wall. The amp really grips the bass on the Harbeths well and makes it tight and formidable, but never abusive.

Again, I can listen to any disk with no fear, and that is so extremely valuable to me. What a sense of power that my system isn't dictating my musical tastes or moods. But, nonetheless,
SACDs sound extrordinary, with real focus and drive, but still relaxing, so I know the Harbeths do reflect the benefits of good upsteam equipment.

So, yes, I do miss the live, totally natural, liquid, you-are there sense you get with more sophisticated speakers with great recordings, but I need to live in the real world, too. If I only listened to classical, I would have stayed with the Kharmas with their extreme differentiation of tonality and layered micro-spatial cues that were really a joy, but I need to hear the Beatles and Boston and Blood Sweat and Tears and Chicago and Carole King and all that great British Invasion music without any abuse or abrasion to trigger those important synapses in my brain.
I placed the above comments as a review so I can add to it later and maybe answer some questions. The review should show up soon, I expect.
I custom made a stereo rack to match the Sound Anchor stands that my Spendor SP100's sit on. I filled 2x4,2x2,1x1 steel tubing with silica sand. Silica sand was plenty dense, heavy and dampened steel perfectly. Steel likes to ring.
Any clay kitty litter will do fine. I just got a pair of Skylan 4 post stands for my Monitor 30's, filled them about 2/3 full, 5 pounds per column, with unscented store brand kitty litter. I've been using kitty litter in metal stands for years. It was recommended to me by a guy who has been a high end dealer for over 30 years. At first, I was surprised that Noel recommended it, since Skylan stands don't ring the way metal stands do and it seemed to me that the only reason to fill the columns is to add weight and mass. But the more I thought about it, the more it made sense.

Anyway, the Skylan stsnds are terrific. Big improvement in bass definition, clarity, soundstaging, depth and imaging. It's like the speakers are suspended in air, but are absolutely stable. Terrific jump factor (which I noticed when my dog jumped).