I've seen quite a few people go the submerged route and none of them got great results.

I could see the benefit of saving money on water blocks and such if it would actually perform better than air. That and if it really does smell.... 75 gallons will run you out of your house.

It's not worth throwing the fish out. (I like my aquarium. I take good care of it.)


EDIT: If you could find a way to take the oil sub zero then it might be interesting.