Center brace fix ?

[Ram3500]

I just discovered that my center brace has pulled free of the silicone on my tank I have a 90 gallon rimless tank it's been set up for about five years . I have emptied about 20 gallons to relive some pressure as the back of the tank was bowing out. My question is do I just use regular aquarium silicone to repair the brace and how long would it need to dry before removing the duct tape that I have holding my tank together ? Any tips ? Thank god for duct tape