Pros and cons of lava rock
 

I've been reading a lot about using lava rock for vanda's but I didn't find any thing about them here or maybe I just missed it when reading the threads on potting and repotting, could I use with other orchids too, I'm trying to learn as much as I can about growing and care of my orchids.

Yes it can be used for many orchids,I buy mine at a big box store,a medium sized bag is quite inexpensive. With some orchids you can use it right out of the bag, with others you can break up with a hammer. I have some Cats.in it some Dens. and others. It does hold quite a bit of moisture,but it can also be used for some that like to be drier, it is really quite versatile! A lot depends on your growing conditions like any other medium. It is like everything else,you kind of have to go by trial and error. The hardest part is breaking it up to get the right sized pieces! Get a big hammer..lol...Jean

I use it with my Phals to take up an extra space in a pot and to add some weight to some pots that tend to tip over.
My only difficulty with lava rock is sticking the skewer inside the pot, so I have to rely more on watching glass fogging and moisture droplets. And yes, finding the right size! :blushing:

Agree with the previous post - depends on what you're trying to achieve.

I use lava rock a lot especially in the bottoms of pots to help stabilize them and because here at the beach it is always around 50-60% humidity and media doesn't dry as quickly as I would like. A lot depends on how you grow your rochids. If you grow with just lava you can usually water to your hearts content. It dries fairly quickly. The nice thing about it is that it holds moisture yet doesn't get waterlogged. Here are a couple pics. If used with bark and moss it is the best of worlds. Oh yeah. The phal lived and is doing great. Flowered twice and still in lava.

Does lava rock leach out anything objectionable? I've seen red and grey varieties, is there a difference in their suitability for orchids?

I've been rinsing and a lot of "dust" comes off the rocks. Shoudl I be concerned? I'm new to lava rock, but am planning to use it more as a couple orchids that I bought in rock are thriving in my conditions and I plan to use it in some baskets since it doesn't break down.

I haven't used lava rock by itself for vandas, but I do mix it with other mediums. I use lava rock for semi hydroponic culture and it works beautifully. I'm sure that it would work well alone in vanda baskets but mixing it with coconut chips or moss allows you a few days before you have to water and the pot isn't as heavy.

I use lava rock for most of my orchids, including my vandas and aerides. I use plastic vanda baskets. Provides humidity to the roots and leaves above. I have to water daily when it is really cold but I haven't really had problems. Because you can use it forever, it needs to be flushed well once a month. In the summer, the rains do a great job.

I'm now thinking I might try lava rock because I need to buy more mix for my new orchids and would love to see how they grow in it, as soon as summer gets here they all can go out under the patio where they get lots of light and watered by the rain

It is cheap and it lasts a long time. Just be sure to wash it well.