I used to have lots of live rock crammed in my sump. After my last major sump cleaning I left all the rock out. I much prefer a nice clean sump now with no live rock. Instead, I float dish washing pads in my sump for extra filtration. They are much easier to manage and cleaner.

http://ecx.images-amazon.com/images/...AL._SX466_.jpg

And unlike live rock they also add a nice splash (pun intended) of colour to the sump. :biggrin: