Odd question

[BrianKC]

Drain the tank and clean it completly with a mix of vinegar and water. Make sure the rock in the sump dont have any, they can be small but my guess is thats where they keep comming from

^^^ this

I might even just move an extra powerhead or two, and the heaters, to the DT for a full day (or two) and let the sump completely dry out before putting it back in service. Your DT will be okay for a day or two without whatever you're doing in your sump.