Lava Rock As A Biological Media

[fry_lover]

Has anyone tried this before?

I have decided to replace some of my mechanical filtration in the Eheim external's with a bit more biological media. I decided to take a hammer to some excess lava rock and then rinse it under the water to get rid of the very small particles. I ended up with lots of lava rock bits in the 1"x1" range. I then stuffed this into a tray in the external.

I am assumming that becuase lava rock has lots of tiny gaps / holes in it, a fair bit of bacteria will colonise it and effecively make it a biological media.

Just wondering if anyone has tried this and/or agree's it will work as a biological media (obviously perhaps not quite as well as traditional biological media)

 

[OohFeeshy]

It will work, but the pores are of a bit of an awkward size- slightly too big to not let any waste in, too small to not get blocked easily. It also fragments pretty easily, so is liable to potentially bum up the impellor with little bits of grit.

 

[fry_lover]

It will work, but the pores are of a bit of an awkward size- slightly too big to not let any waste in, too small to not get blocked easily. It also fragments pretty easily, so is liable to potentially bum up the impellor with little bits of grit.

ah, good points, especially about fragmenting, i appreciate the heads-up there. Perhaps i should place a fine layer of sponge or filter wool over any tray i use the lava rock in.

cheers for feedback