Plenum System advantages?

[mrpope]

what do you guys think of the whole plenum thing? Any reasons not to use one?

 

[Brad]

I put a plenum in my sump, but not in the main tank. I was afraid that the sand would move around and leave the plenum exposed, which wouldn't look nice. In hindsight, that definitely would have happened.

I can't say if the plenum helps or hurts. My system seems to be working well with one in the sump, but my system may have worked just as well without it.