Air stones aren't as important as good air pumps. I use so many different types of airstones.. I only use Active Aqua Air pumps.
http://www.activeaquahydroponics.com/
Hi, I have one dwc bucket and used the 6-8 inch ones you buy at the fish tank store. They work abs you need to replace them every grow—- they are cheap abs easy to find! Good luckN. ✌️🏻💚🌿