Alright I need help finding pumice. I have called so many places... home depot? Nope Lowe's? Nope Garden centers? Nope Building supply stores? Nope Feed stores? Nope Count less hydro stores? Nope Online I'm only finding it at 15quats for 25-50$!!! I'm not looking to spend 100+$ on this and I fell is a complete rip off. So please I'm asking does anyone know where to get this stuff for a fair price. I live in southern California. Do I have a different option to use? Pumice is lava rock correct? Could I buy lava rock and crush it myself?