Haha thanks, guys. We had a several-hour power outage this morning, and knowing that the QT was overstocked, I had to make a decision to either leave them all in and hope they survived, or lighten the load so they didn't have oxygen troubles as quickly. I opted to put one male molly and the hawkfish into the DT with the female mollies. Everyone survived the blackout. I am, however, thinking that I really need to buy a backup power source before I stock the DT further. Even this made me nervous.
@Maritimer it's not bringing velvet into the DT that I'm afraid of. It's whether I might already have it in there from shared equipment, such as my net. All my fish are cured, thankfully, but I'm scared to death they'll catch it from remnants in the DT.