sump or not???

I waited for so long until I got a tank and sump but I'm still having
problems with nitrates. one or two people have suggested that with the
amount of LR in my tank that that's all I should use and dump the sump.
would this be a good idea.
I could use the water in the sump and remove the media leaving it like a
reservoir of salt water with a skimmer and heater with some calerpa in the
base.
is this latter idea sound or bunk.

Robin