
Originally Posted by
privet01
Seems that the forum has been having technical issues the last four or so days and no one, including myself, have been able to reply to any posts or even view them while logged in. So hopefully that accounts for the lack of responses.
I think you got some answers elsewhere, but just so I can throw in my opinion...........
Most lava rock is probably inert. So certainly that will make it good for a drainage layer. It's porous and should favor the growth of beneficial bacteria which help maintain your water quality.
The lava rock I've had in the past tends to be sharp, so I don't like it to be exposed to the frogs to crawl over. It's used in aquariums quite a bit. Not without it's nay-sayers though.
It's probably more a question you should ask of a geologist. Is all lava rock created equal in terms of whether it does or does not leach bad stuff into the water?? I don't know. If I had a cheap source for lava rock compared to other options, I'd certainly try it and see.