volcanic rock or lava rock for biosand filter medium?

[Guest]

#806

My measurements on volcanic sand in Costa Rica indicate that you get up to 40 % passing a 0.15 mm (100 mesh) sieve. this should not be more than 10 %. Hence, this sand is WAY too fine. It will give a very low throughput and probably well below the 10 cm/hour (100 liter/m2 of filter surface and per hour.

[Guest]

#804

hi i am from mexico, and i can get lava rock easy, so can i use lava rock as a medium to buil my bio-sand filter?
my e-mail is robertfs3@yahoo.com.mx

[Eric]

#805

Hi

Any inert media should be fine as long as it has characteristics along the lines of other media – see information about grain size on the website.

Cheers

Eric