I just got back from the hydroponics shop to get some net baskets for re-potting and I took a stroll through the rest of the shop. There was a sign stating that German company who made the Hydroton baked clay balls used for hydroponics and semi-hydro orchid culture has gone out of business due to the clay mine being used up. Now the new stuff is called "PlantIt". It's the same price per bag & same size clay balls but is more brown than orange in color.
Just thought I'd post incase anyone is looking for Hydroton, you'll need to look out for the new name now.