Is lava rock a workable alternative to regular aquarium rock?

[MarSch]

I have heard that lava/volcanic rock can be used in place of regular dry rock. Does anyone know if this is true?

In New Zealand, "regular" rock is heinously expensive - $20 per kg. Lava rock, on the other hand, is comparatively cheap at $6.50 per kg.
It is very porous, so seems like it would make a good home for bacteria, but I'm just not sure if it is safe in terms of leeching chemicals.

This is what I'm looking at: https://www.bbqsdirect.co.nz/flame-diffusers/806-lava-rock-2kg.html

Any advice would be appreciated.
Thanks!

 

[joseserrano]

Lava rock leaches something, can’t recall what but not a good idea

 

[Crustaceon]

I’ve seen it used with no real problems. The caveat is I believe it can leech iron, but not always and that shouldn’t be an issue anyways if you do regular water changes or use the proper absorbing resin. After a year or so in your tank, it’ll probably expel everything and be just as safe as normal live rock anyways.

 

[MarSch]

After a bit more googling... seems that you can never be as confident in the chemicals in lava rock as with proper reef rock. So, while it is often fine to use, it can also often leech metals.

 

[Ratherbeflyen]

I've been running my tank on 100% black lava rock for 2 1/2 years with no ill effects.