[Powder Blue107]

What I plan to do is lower the water level 2 inches below where the bottom of the overflow will sit and silicone in the three-sided overflow but I have some concerns

When I silicone the Overflow how long should I wait before filling the tank back up?

Should I take all the tank inhabitants out of the tank including my two corals before doing this project?

What type of silicone should I use? Preferably something that's non- yellowing

I understand that silicone inside the tank will give off a strong odor but will this affect tank?