If i put live rock down in the sump, replacing the bioballs, will that help?

putting heaps of live rock in your sump is in my opinion much better then bio balls, bio balls tend to be nitrate factories. the reason being is balls cant change the chemical state of nitrate to gasious form, hence the higher readings. if you load up the sump tank with live rock and let the bacteria reproduce, it would be the same as having heap in the main display tank. You cant perfect what nature has already created.
Refugiums are just a volume of water with constant water flow, filled with a large sand bed, generally coarse sand on the base and finer sand on top, with some sort of macro algea plants growing in there. You have a light on it on the opposite time as your main tank, this enables the plants to absorb nutrients which make bad algea grow in main tanks, also helps break down nitrates. Hope this helps in lamens terms
CHEERS

thanks man. I have only had my tank set up for about 3 months now. And everything is going great, so I think i might just wait on one.