Read this as well as the quail foot problems before you build. It may save you from learning the hard way. Hope this helps all.
I have had quail for several years now, I even bought the special coated wire, breeder battery for quail. I also used galvanized wire (harp point down). With the coturnix quail BOTH WIRE TYPES CAUSED BLOODY FEET. I now use the heavy plastic rabbit rest pads, they have nice oval punch outs in them and lock down to the wire. I also use the ornamental grass cut in long strips and put in with them. they rest on it and seem very content, and it's easily changed. With the rabbit guard they are easily hosed off or brushed off. I agree with all on a dusting box. They seem to enjoy a water bathing pan as well. If you have the room add these items, or do an add on area to your pen. simple and makes for some healthy happy birds. I now have Bob whites as well. I add pine bows to it for a natural cover and they roost on it and hide in it. Just chage with fresh when needed. Good luck.
I just made a dusting area from a large cat litter bucket, cut the back side out, leaving a 4 inch lip on the bottom. Fill it with dry dirt, sand, and food grade DIO. Earth. They love it, as they throw it around, it goes on their back (what they want in the first place) and it stays in the bucket so you aren't refilling it all of the time. I am going to add a section to my Bob pen for this and an area for living clover (a dish pan size) it can be watered and kept alive. Give them another thing to peck and scratch in. Plus they love the live greens and grasses. Keeps them from pecking each other and adds another natural resting area. I am constantly coming up with idea to improve their caged lives. I raise them mostly for enjoyment, but will hatch out a bunch of coturnix for the smoker. Wrap em with a slice of bacon and smoke em. or babe in the oven. ENJOY.
Update on cat litter box duster. They WILL lay eggs in this, I am going to turn mine 90 deg., cut out a portal on the back (bottom) of bucket to see into and retrieve eggs. simple fix, but hadn't thought of them having eggs in it when I first put it in. Always learning something, haha