Lava Rock information

[Hound Dog]

I have seen many people starting to use Lava Rock now but find information kind of scattered on the subject. I first caught wind of it with a post on column packing by Mash Rookie. I tried some in a 2" x 3' column that has a centering ring on an LM rig running on a propane burner. I broke up some rock that was for a gas grill and was a mix of red and black. I rinsed and boiled it a few times until the water stayed clear before adding it.

Lava Rock .jpg

This is a sample of what I broke up. I believe I should have made it a little smaller. There was no restriction in the column what so ever. In the past with copper mesh I had always had it so there was a bit of restriction in the pipe blowing trough it. When doing a run of All Bran low wines with this size of lava rock I could not get above 93%. With this same setup and tight copper mesh I was able to maintain 95% at about a quart an hour. This is why I believe smaller tighter packed rock may perform a bit better.

My next build will be a 3". I would like to hear what others think of their experiences with Lava Rock to judge what size pieces I should run.

Please chime in as to what you have been using and what your results are for all of us to learn from. This is just an attempt to consolidate information on this subject. Pictures would be appreciated!