Tank Leak! - What Silicone to Use?

[howdy20012002]

you will need to find some silicon that doesn't have anti-mildew additive.
I don't think there are anymore brands that you can use that you can buy at a hardware or lumber store anymore as they now all have the anti-mildew additve.
you are going to need to get some from a fish store that is specifically designed for aquariums.
ideally, you should redo the whole seam
however, bare minimum - you will have to drain the tank to at least below the leak
I personally would scrap away all the silicon around where it is leaking with a razor blade - don't cut between the glass just the seal bead running along the inside of the tank.
then apply a seal bead along the area.
wait at least 24 hours and refill the tank.
wish I had better news - it is going to be a pain in the a$$
good luck
Neal