Redox,
Glad this was still in QT!
Machado,
I think if you run a skimmer and sump, that there is still enough gas exchange. If it was just a tub with no other aeration, then I would not recommend it.
I also think HRVs are a great addition, though pricey. For some, they are the only way to prevent mold and rot, and therefore worth every penny!