s/h hydropon alternatives?

[Vanda lover]

I couldn't get hydopon easily here, so I have been growing in lava rock. I'm finding that it works very well and is much cheaper. It also won't roll away If a pot gets knocked over. I have heard that the drawback is that the minerals will build up more, but if it is flush often, that shouldn't be a problem. It may need to be changed a little sooner.
Perlite floats too easily and would make it hard to keep plants in place.