I should clarify what I mean by the GE I being "acid" cure and GE II being "ammonia" cure. When you use MOST silicones they are "acid" cure. They cure through a chemical process using Acetic Acid. That's where the vinegar smell comes from. Vinegar, which we use in the hobby to clean everything with, is Acetic Acid. GE II uses ammonia in the same way to cure. Now, given ammonia is a dirty word in the hobby, you should always err on the side of caution when using any ammonia cure silicone and allow AT LEAST a week to fully cure. Preferably two weeks.
I did a great deal of research into what was in different silicones before I re-sealed my first tank or built my first sump. Silicone is inherently mold "resistant". I was never even able to find a "Mold Resistant or Inhibitor" in the MSDS for GE I window/door/attic, GE II window/door/attic, or GE II kitchen/bath. A call to GE netted no answer to the question of what the mold inhibitor ingredient was either. For the record, I was advised by GE that they DO NOT recommend the use of ANY of their silicone products to be used in aquariums. I called DAP and got the same answer, with the exception of their "Aquarium Sealant". Upon asking what made the "Aquarium Sealant" safe, I got an answer of "I don't know".
I suspect after reading all the horror stories on the forums the problem isn't the silicone, but the impatient aquarist that doesn't allow enough time to cure. All the stories are the same. "I re-sealed a tank I just bought with GE II the day before yesterday. It's a 55 gallon freshwater. Yesterday, I put my gravel in it, filled it up with tap water, put a new HOB filter on it, and put 10 tetras, 3 Jack Dempseys, 5 Oscars, 15 Gouramis, and a 15" Pleco. Today, everything is dead except 1 tetra. What do you think the problem is?" Inevitably someone replies "I bet it was the silicone. You didn't pay enough for it. You have to use the stuff that says aquarium on it."