Ah, okay thanks. Shortly after i asked you my question i actually realized just about every silicone sealant says "do not use below waterline". An associate in Home Depot actually told me "all silicone shouldnt be used below the water line". I then asked him, then how come every fish tank that has ever been made has silicone that goes below the waterline and stays below the waterline for an extended period of time. His response was "you got me there"
My best friend was actually flirting with him earlier and i told her hes not worth her time. ;)
I promise you many people have and always will use GE 1 silicone for their tanks. That includes me. believe it or not, GE sells the very same mix of silicone to resellers who mark up the price to sell as relabeled aquarium safe. They have agreed to put the words do not use below water line in return for bulk orders shipped to aquarium specific retailers.
I do stress that you allow the silicone to cure a week. Once cured it is completely non toxic.
However if you demand the very best, strongest and the 1 major aquarium manufacturers are using get GE Momentive series RTV103 for black and Momentive RTV108 for clear. These two types are available at the local Grainger or online.