Zoo med hydroballs

[Optimist]

I've bought them in a pinch. I started to like a brand I got on Amazon, because I had prime which was more like 5 pounds for 15 dollars. They were larger and had odder shapes so they had more air movement between them. They were made for the hydroponics industry. If you live in one of those bigger cities you can probably get a humongous bag at a hydroponics store. I am in a little town of 30K and no such thing exists around me.