Just to expand on that a tad bit just because it says 100% silicone does not mean it won't contain those "cides".Depending on the temperature, humidity, and type of silicone, it takes about 24 hours for it to cure.
Surface prep is important - the glass needs to be absolutely clean for a good bond.
As for the type - many work, but if the glue is exposed to the water by all means avoid silicone with -cides in it (fungicide, algicide, whatnotcide).