It took FOREVER until that stuff was stable imo. I also personally think it adds to fert build up problems myself but I'm known to grumble about hydroton in general so you have to take what I say with a grain of salt.

Higromite Here is what I use and I like it but it does have its own drawbacks. Among them....weighs ALOT (weighs about how it looks....) and has the same dust issues at the beginning as hydroton so you have to rinse it and for some reason algae LOVES this stuff and will grow like mad on it so its best to keep it covered. I will say that since I've started using it again my plants are much better, healthier and yield better so I'm sticking with it.