Yes you can use all the coarser material. Just try and get out the finer material that is less than 1/8 inch or smaller. This finer material blocks air flow through the mix which then causes stagnant conditions in the root mass and rot.

I'm finding that with the "lava debris" and other coarse material that water flows through pretty easily. Looks like this type of media requires a good soaking in a pail of water to get it saturated. I'm doing that about once a week and then in between I periodically drench the new roots with a spray bottle.

I repotted the plant with the new growth towards the middle and pointed upward more. This results in the other leaves to be tilting downward somewhat dramatically... but I figured the priority here is for the new growth.

http://i716.photobucket.com/albums/w..._new-bulb1.jpg
http://i716.photobucket.com/albums/w..._new-bulb2.jpg