old-fashioned fibresand used to work a bit like that. what kind of sand have you got?
my best advice would be to look into a surface like Springride which stays on top and keeps the sand from getting churned (although it's not proof against tons of lungeing.) it's flat rubber pieces with holes in, which sort of jigsaw on top of the sand roughly, and keep the horses on top, if that makes sense. i've had it on my last arena and this one, i rate it so much. PM me if you want more deets.
Yes, I've just ordered some to add to my silica sand surface in order to bind it more. You can get waxed or unwaxed (which is cheaper). The guy I spoke to at Martin Collins said that buying waxed fibre for an outdoor arena was a waste of money, and the unwaxed in perfectly good enough. If you are adding it to an indoor surface however, you would need the waxed fibre unless you were prepared to spend your life watering it.
The fibre comes in bales. You spread it over the surface and then harrow it in and roll it.
Equestrian surfaces also do fibers to add in. They come in three qualities from them. Prices vary quite a bit. The middle one for a 25 x 50 metre arena to add to "good quality sand" is something in the region of 4k stg. I think. Adding in fibres won't give you anywhere near the result of a premixed complete surface but the ones I've seen have been very good and I hope, fingers crossed, that mine ends up the same when we finally get it finished!
A cheaper option is probably to use a crumb rubber additive but that has it's own pitfalls.
Thanks all. Following up Martin Collins lead but Equestrian Surfaces only seem to do a fibre/sand mix with no email address (?!). I seem to remember seeing something called Turf Float but can't find anything out about it yet.
I've got a sand and dirt mix so don't know whether it will work that well but am trying to avoid rubber. I want a surface that is more springy than sand but not as springy as rubber.