Importance of sumps and LR in agg. setup

[chopper320]

How important is a sump in an aggressive setup? Would 2 hang on the back filters be good enough or should I worry about an overflow and building a sump.
Also....I have about 25#'s of LR in my 55gal and was planning on adding another 20#'s or so. Just recently I was told by 2 different petshops that adding LR in an aggressive tank with Triggers or Puffers and such is virtually pointless since they eat all of the goodies that make the LR beneficial. Is this true? And does this mean it is ineffective as a filtration method?
Thanks and sorry for the long post!

 

[saltwater4me]

You can add lr in your tank, but your lfs is right, triggers and puffers do eat all the goodies on the lr.If you add lr make sure its cured, because if it's not you will have another cycle in your tank, and your fish may die. If you want to know wether or not it's cured, smell it if it smells bad its uncured, if it has no smell its good.