I'm considering removing all of the bio balls from my trickle filter and replacing them with Poret Foam from SwissTropicals. I emailed SwissTropicals, who suggested using 2x20ppi and 3x30ppi sheets, laying them flat (greater surface area). I've been searching and haven't found any pictures of a bioball tower filled with poret foam in this way. Has anyone done this? experiences? pics? Thanks.