Sand in my run?

https://www.backyardchickens.com/t/444759/got-sand-you-should

You may find the above thread helpful. I wear an N95 mask when I scoop my sand every day with a kitty litter scoop in my coop and nest boxes. It works great and I love it. Sand dust is VERY bad/dangerous to breathe.

For the run, you can end up with a hardpan layer if it gets wet a lot, and you may need to add more sand or remove the hardpan. It depends on the individual circumstances as to whether it will work for you.

I love adding sand outside around the waterer when it gets muddy, but it washes away and I haven't bothered to do it lately.

I recommend doing a small test area with sand and see how it reacts to your weather, and additionally don't add more sand than you would care to shovel back out in a year or so if it ends up hardpanning on you.

I buy the washed sand and have it delivered by truck, and keep it covered with a tarp. I used to buy the play sand bags from Home Depot and that worked out great but I wanted cheaper. The mason sand at Home Depot is wet inside the bag but was cheaper than the play sand. The moisture wasn't good in the coop and so I switched to truckload method.