I know you don't need to use it any more, but for others looking ...
NO, do not use any silicone for kitchen/bath or tile/tub. Those contain mildewcide & not aquarium safe. Also, do not use anything but clear, <So white is out!>
You want 100% pure clear silicone (with nothing else added), normally this is marked for "Windows & Doors". GE Silicone I used to be good, but I read that there is a reformulation & it may also contain mildewcide.
I normally use a Hardware store store brand (Rona -- only in Canada) 100% silicone. It is marked also "for aquariums use".