GE Silicone-1 is the thing to use, because it has no chemicals in it to kill mold, algae, snails etc. Silicone-2 is for bathrooms and is anti-mold. Don't use it in aquariums. Most everyone here knows this, but it bears repeating.
Also please note this: I recently bought a tube of Silicone-1 and it was defective. It never cured after weeks.
I have never before had this occur in 40+ years of use**. I have great faith in this stuff in aquariums and on high-rise construction. As an engineer I did plans for the windows on buildings from 1 to 35 stories that were sealed with GE-1.
But before I seal another tank I will open the tubes, shoot small test samples, and wait a day. 24 hours in normal temp and humidity is enough to effect a good seal, so the samples should be substantially cured, like solid rubber.
**I have seen failures where procedures were violated, and things actually came loose. Procedures on big jobs usually require test samples to be made and reviewed by the appropriate person. There is usually a full-time inspector, paid by the owner, to do such things. We would even build a portion of the building wall/windows in the lab, and test it first.