I have a skimmer and a waterfall basin. The skimmer came with 1 square cutout of filter media. I was wondering if that was the best for the skimmer or what the best setup for the skimmer would be? Also for the waterfall basin/bio falls...I was thinking about doing a few layers of filter media pads and some bioballs/lava rock? Whats the best arrangement for filters in the waterfall as well? Are bioballs better/worse than lava rock? Should i have both lava rock and filter pads? Just looking for the best setup to filter my water Thanks!