Don't use household anything,
They are right,,,,100% silicone is what you wanna use,
Now before the other forum I visit crashed, there was a thread there, someone told what G.E. one to use, It's GE 100% silicone 1 or II, but I don;t recall off hand,
Now reading lables will not always tell you if it is or not safe for aquar.,
one of the Co. that it use to say it was safe for aquariums, had a lawsuit on them becuase someone used it and the tank didn't hold or killed all the fish or something......
So it was removed from the labels.
Just an added Note,
if your resealing a tank, DO NOT take the silicone out of the seams, leave that alone and just remove the Silicone on the exposed flat parts of the glass,
Most of the 100% types of goopy are not as strong as the stuff on the tank now, and will save you allot of headaches down the road more then likely..