Hi everyone! Hoping to benefit from everyone's expertise here before setting up my run this weekend! I have 4 3-week old chicks that are quickly outgrowing their brooder. I got a used Eglu Cube that I'm planning to set up in my suburban backyard. (In the future I'm hoping to build a WIR, but for now I'll just use the 10x4 foot run that came with the cube. The chicks will also spend a fair amount of time free-ranging under supervision and hanging out in our large side yard.) Our yard is full of slowly-draining clay, so I'm hoping to avoid having a big smelly muddy run by building the run up a little (as pictured below) and using sand. Initially, I was planning to use some kind of edging (either redwood/cedar boards or composite boards), then 3-4 inches of drain rock to improve drainage, then 3-4 inches of sand. However, the guy at the lumber yard said the sand would fall through the drain rocks and I should put landscape fabric in between. So now I'm torn about whether I should even bother with the drain rock. We don't get a lot of rain here in California, but I really don't want the run to smell since our neighbors are pretty close by! So - should I use drain rock or is it not really necessary? I could always use the drain rock around the edges of the run and then just sand in the run itself. I also have to make sure that predators (including my small dogs) can't dig into the run, which if the whole thing is sand might be a problem. (There is an apron on the cube run.) Thanks for any help!!