# Lava rocks as bio filter media



## petlovingfreak (May 8, 2009)

Ok, so I've been thinkin about trying this for a while, I want to use lava rocks in my canister filters as biological media. Lava rock is very course and has a very large surface area for it's size. I am of course going to rinse it VERY good, to get all the dust off. I figured it'd work very well and is A LOT cheaper than buying ceramic rings etc. Has anyone tried this before?


----------



## bmlbytes (Aug 1, 2009)

Sounds like a good idea. Some lava rock floats though so it may be kind of a pain to get them all to sink in the water


----------



## Toshogu (Apr 24, 2009)

So long as you get the pebble sized ones you should do fine.


----------



## petlovingfreak (May 8, 2009)

They wouldn't have to sink in the water because they'll be in a basket in the canister filter. And I'm picking the small sized ones out of bag of big ones I bought, put them in 2 of my canisters today.


----------



## lohachata (Jan 27, 2006)

you can also break them up to make somewhat smaller rocks..lava rock will make an excellent biofilter...


----------



## petlovingfreak (May 8, 2009)

Yeah, I don't see why they wouldn't work great, they have a ton of surface area. I will be putting them in the other few canister filters I have in a few weeks when I clean them out also.


----------



## emc7 (Jul 23, 2005)

I've heard of them being used in sumps, but not canister filters. The only drawback I can think of is if pieces get loose and scratch the impeller. And just having to handle them to clean the filter. They can cut skin if you aren't careful.


----------



## petlovingfreak (May 8, 2009)

yeah, i rinsed them very, VERY good to make sure no small particles come loose. And as for cleaning the filter I don't clean the baskets that hold the biological filtration, to preserve the good bacteria. So no handling required, and they aren't that sharp, I've made numerous caves/ornaments out of them for the fish and never cut my fingers, though they are rough. THey seem to like them though.


----------

