Question using sintered glass and lava rock in sump

[michael]

I just got a gallon of eheim sintered glass and eheim lava rock. For best filtration should I submerse these in mesh bags or have it so the water trickles over it like bio-balls? thanks

 

[michael]

no one has advice?

 

[Nic]

mike i have both along with seachem matrix all submerged and i like it alot better...

 

[CHOMPERS]

If you have good mechanical filtration, then you don't need to put them in filter bags. The bags will make it convenient in handling if you ever need to work in your filter.