Is this a fish only tank or do you want coral and have a lot of live rock? If it's the latter, you could slowly remove the bioballs and make that area a refugium.
Otherwise, you could make do with the rest of the sump but I would not personally want a bunch of sand near my return pump.
The other option is to add the refugium external to your sump and have a powerhead feed it and drain back into the sump. |