Sump Rock

[ctmedman]

I have bioballs in my sump that I would like to get rid of and replace with another mechanism of biological filtration. Some have recommended that I fill the sump up with rubble rock but I was wondering if there are cheaper alternatives. Maybe lava rock?

TIA

 

[Brenden]

Hirocks.com rubble is not expensive. I use base rock rubble for everything below water and have bioballs on top of that above the water line.